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  1. Trailer Tongue Lock
  2. InfiniteRule
  3. Fits 2 Inch Ball
  4. Fits 2-5/16 Inch Ball
  5. Keyed Unique
  6. Latch Lock
InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers - 2" and 2-5/16"
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InfiniteRule

InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers - 2" and 2-5/16"

Part Number: IR66FR
183 Reviews | 47 Questions
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$66.93
 Trailer Tongue Lock
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infiniterule trailer tongue lock latch
infiniterule trailer tongue lock universal application fits 2 inch ball 2-5/16
infiniterule trailer tongue lock fits 2 inch ball 2-5/16 ir66fr
infiniterule trailer tongue lock latch for cast demco ez-latch couplers - 2 inch and 2-5/16
infiniterule trailer tongue lock latch universal application for cast demco ez-latch couplers - 2 inch and 2-5/16
infiniterule trailer tongue lock fits 2 inch ball 2-5/16 ir66fr
infiniterule trailer tongue lock universal application fits 2 inch ball 2-5/16 ir66fr
infiniterule trailer tongue lock universal application ir66fr
infiniterule trailer tongue lock universal application fits 2 inch ball 2-5/16
infiniterule trailer tongue lock latch fits 2 inch ball 2-5/16 ir66fr
infiniterule trailer tongue lock latch universal application
infiniterule trailer tongue lock latch universal application
infiniterule trailer tongue lock latch
infiniterule trailer tongue lock latch fits 2 inch ball 2-5/16 for cast demco ez-latch couplers - and
infiniterule trailer tongue lock universal application fits 2 inch ball 2-5/16 ir66fr

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0 trailer tongue lock infiniterule universal application ir66fr
0 trailer tongue lock infiniterule latch for cast demco ez-latch couplers - 2 inch and 2-5/16
0 trailer tongue lock infiniterule fits 2 inch ball 2-5/16 ir66fr

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InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers - 2" and 2-5/16" customer photo
InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers - 2" and 2-5/16" customer photo
InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers - 2" and 2-5/16" customer photo

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Heavy-duty, stainless steel lock provides superior security when locking your cast Demco eZ-Latch trailer coupler or gooseneck coupler ball. Third-party-tested pin has a 42,000-lb shear strength. Great Prices for the best trailer tongue lock from InfiniteRule. InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers - 2" and 2-5/16" part number IR66FR can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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InfiniteRule Trailer Tongue Lock - IR66FR

  • Fits 2 Inch Ball
  • Fits 2-5/16 Inch Ball
  • Keyed Unique
  • Latch Lock
  • InfiniteRule
  • Stainless Steel
  • 2-15/16 Inch Span
  • Universal Application Lock

Heavy-duty, stainless steel lock provides superior security when locking your cast Demco eZ-Latch trailer coupler or gooseneck coupler ball. Third-party-tested pin has a 42,000-lb shear strength.


Features:

  • Flush-style lock fits your 2" or 2-5/16" cast Demco eZ-Latch trailer coupler or gooseneck coupler ball
    • Coupler latch lock secures your trailer to your ball mount
  • Heavy-duty stainless steel construction
  • O-ring protects internal components from dirt and grime
  • Weather-resistant, tethered dust cap keeps water and debris out of keyway
  • 2 Keys included
  • Made in the USA


Specs:

  • Application: cast Demco eZ-Latch trailer coupler for a 2" or 2-5/16" ball or a gooseneck coupler ball
  • Shear strength: 42,000 lbs
  • Pin dimensions:
    • Overall length: 4-3/8"
    • Diameter: 1/4"
    • Inside pin length (span): 2-15/16"
  • 1-Year warranty


Note: This lock will only work with Demco EZ Latch couplers that are cast and not stamped.


Extensive Testing

InfiniteRule products undergo extensive third-party testing to determine shear strength. The shear strength is determined by placing the locking pin in a stress position and subjecting it to increasing force until a required proof load (maximum force received without deformity) is met or the pin fails. These locks have a shear strength of 42,000 lbs.



61130-D Infinite Rule Security, Inc. Lock - Stainless Steel Trailer Tongue Latch Lock - 1/4" x 2-5/16" Span

Replaces IR56FR (61121-D)







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Customer Satisfaction Score:

Ratings & Reviews

4.7

183 reviews
5 Stars
(151)
4 Stars
(25)
3 Stars
(3)
2 Stars
(1)
1 Star
(3)
Review Sort Icon
by:
Excellent product it is a easy and effective way to keep your trailer secured.
by:
Excellent product, but the instructions could be clearer
by:
Works well for the Demco hitch. Just what I was looking for.
Mike profile picture

Mike

1/26/2026

Works well. Only complaint is needing to screw the key lock in and out as I install and remove the lock.

by:
Very nice piece. Fits perfectly. Very high quality.
by:
Very well made ,The only reason I gave it
A 4 not a 5.Because I thought It would go over the
Latch a little so the latch couldn’t be pull up on and be
Snapped off . Besides that I really like the look of it .
by:
Easy to use and built well for use on a Demco lock. Very easy to order on li e and arrived when they said it would. I would recommend this product and company.
by:
Works as advertised !
by:
Great product.
Jim profile picture

Jim

2/14/2026

Great. I took a chance on this walk because I felt it would work even though you say it does not work. It works perfectly for the style trailer lock I have and you should be advertising it as up.

Kate F. profile picture
Etrailer Expert

Kate F.

2/16/2026

@Jim What style of lock do you have Jim? I am glad to hear it works, but am curious on what kind of lock.
by:
Works perfectly with my Demco ez latch coupler. Quality material and it came quickly.
by:
works great!
by:
Product as described!
by:
After attempting to go the route of a conventional padlock and realizing that this approach would not work on the unique tongue of my P.J. U7 trailer, I scoured the inter webs for some manner of commercially available specialized locking device tailor made for this application. I found the solution in this robust and very well built lock. The first thing that impressed me right out of the gate was how heavy it was-this ain’t no wimpy thing. I tried it out immediately when it arrived and it fits like a glove, precisely as specified. Perhaps the best part for me is that this lock is made here in the United States! YES!!! I ordered two of them just to have a spare and I’m thankful that I did. I could not be happier with the quality. I think the price is reasonable, too, considering the quality. Two thumbs WAY up and 5 stars all the way.
by:
Well I just out it on, seams ok, Time will tell. Thanks
by:
Fitment was great exactly as advertised
by:
The guy on the chat service helped me out by finding the proper lock for my trailer. came quickly, neatly packaged . and fits perfect. Thank you again for your services.
by:
No clearance when trailer is hooked up. First turn I took using it snapped.
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Lazer S. profile picture
Etrailer Expert

Lazer S.

11/25/2025

Wow, that was not supposed to happen. Sorry you had to deal with that, Kevin. What brand ball mount are you using? It looks like we got a full credit issued back to you, but is there anything else we can help with? We may have a lock that will work better.

by:
Overall pretty good, but the stem should be 5/16-inch diameter to better fit instead of 1/4- inch. A larger diameter would make the lock more robust. Etrailer ordering, price, and shipping was excellent.
by:
Very well built, nicely machined, stainless steel product.
by:
Nice product. Seems well made and secure. Does take a little while to install because of having to turn the key to tighten it up and locating the spot to remove the key but overall I think it will do the job
by:
Great service start to finish. Excellent product was as described.
by:
Fast and reliable!
by:
Heavy Duty lock for my new Rugged Aluminum Tandem Trailer. First time for a Demco brand coupler. Other trailer locks do not work. Thank you, etrailer for all of my Camper, Boat, Utilty and Car hauler trailer needs.
by:
Great!
Sturdy stainless!
by:
Works great and gives you added security when diving it
by:
Sheila went above and beyond from the get go with me. She took her time to explain to me my concerns and knowledge of what I was buying. When I had the issue with ups. I sent her a email on a Friday evening when it was her time off and she responded back and right away took care of the issue. In my eyes she’s a true team player and good customer service!!!
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Show More Reviews

See what our Experts say about this InfiniteRule Trailer Tongue Lock

Do you have a question about this Trailer Tongue Lock?
  • Recommended Lock for MORryde GooseTech 5th Wheel to Gooseneck Pin Box
    Hey Jeff! The MORryde GooseTech 5th Wheel to Gooseneck Pin Box # MR97MV comes with a Demco eZ-Latch. The best option for a lock is the InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers # IR66FR. This is designed to for a standard coupler but fits the GooseTech as well. Are you replacing a 1621 on your 5th wheel?
    view full answer...
  • What Coupler Lock Is Recommended For The Demco EZ-Latch Coupler On A Big Tex 30SA Trailer
    Hello Brett, thanks for reaching out. For you I recommend the InfiniteRule Coupler Lock # IR66FR. This lock is made specifically for the Demco EZ-Latch couplers, and it will work with both the 2" and 2-5/16" ball couplers. It has a 42,000 lb shear strength so it is a good strong effective lock.
    view full answer...
  • Coupler Lock Recommendation For Demco Channel Tongue Trailer Coupler DM15945
    Hello John. The InfiniteRule Lock # IR66FR is the best lock option for the Demco Channel Tongue Trailer Coupler # DM15945. This lock was made specifically for the Demco eZ-Latch couplers, so it will work great for you. To answer your second question, there is no hitch pin lock that can be keyed to match this lock, so you would have to keep two different sets of keys.
    view full answer...
  • Lock for Demco Cast Head Coupler And Safety Chains
    Hi Kathy; we do have locks like the InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers # IR66FR or ICON # AL78DQ for your # DM37ZR. However, there are no locks that cover both the coupler and safety chains. If you're wanting to leave them on the trailer while it is sitting/stored, I would wrap the chains around the tongue and secure them with a simple padlock like # ML1KA. What kind of trailer do you have?
    view full answer...
  • Looking for Trailer Coupler Locks Compatible with the Demco EZ-Latch
    Thanks for the details Jeff, happy to help! A Demco eZ-Latch coupler is a specific style of trailer coupler that automatically latches onto the hitch ball when you lower it into place. Rather than using a traditional manual latch, it has a flat, rectangular top with a hinged flap, which sounds very similar to what you're describing on your Boatmate trailer. The InfiniteRule Trailer Latch Lock # IR66FR is made specifically for that style of coupler. I can say these will be stronger than...
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  • Which InfiniteRule Lock Fits Cast Demco Brake Actuator
    Hey K, thanks for the picture! That is a cast Demco coupler so you need the InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers # IR66FR. This works with both 2" and 2-5/16" models. What kind of trailer do you have?
    view full answer...
  • What Size Lock Works w/ the Cast Trailer Coupler e88FV?
    Hey Jamie. The Cast Trailer Coupler item # e88FV uses a 5/16" pin to secure it so it requires a 1/4" pin diameter lock like the InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers item # IR66FR. The fixed locking point on the coupler may need to be slightly drilled out to widen it. What kind of trailer do you have?
    view full answer...
  • Can the InfiniteRule Lock for Demco eZ-Latch Trailer Couplers Be Keyed Alike?
    Hey Oliver, welcome back. The InfiniteRule Lock for Cast Demco eZ-Latch Trailer Couplers item # IR66FR can not be keyed alike. To get multiple locks keyed alike that are compatible with the Demco EZ-Latch like item # 12660-97SP, you'll need to go with our etrailer Surge Brake Coupler Lock item # e98887 for a 2-1/2" span or item # e39PR for a 2-3/4" span. Please note that you will need to purchase the locks at the same time and select the "keyed alike" option from the drop down above...
    view full answer...
  • How Can I Secure My Kar Kaddy From a Thief Stealing it While it is Attached to RV & While Storing?
    Hello David, Those are very valid concerns, especially in the world we live in today. I have 2 different locks for you to keep those "sticky bandits" away: 1st lock is the InfiniteRule Lock for Demco eZ-Latch Trailer Couplers - 2" and 2-5/16" # IR66FR, this lock is great for keeping the Kar Kaddy attached to the ball. You can also use the lock while it is disengaged but will probably not deter the seasoned "treasure hunter." 2nd lock let's go a step above, or better yet all the way to...
    view full answer...
  • Will MORryde GooseTech Have Clearance Issues With Bed Rails
    Hey Travis! You won't have any issues with vertical clearance using the MORryde GooseTech # MR27MV. The only clearance issues you might run into is if your 2017 Ford F-350 is the short bed. If you have the long bed this is going to be a really nice upgrade for your setup. You will also need safety chains # GY49GR and if you want a lock for added security you can use the # IR66FR. I'm assuming you already identified your pin box and it has a Lippert 1116 bolt pattern. What kind of 5th...
    view full answer...
  • 2014 T@G Trailer A-Frame Coupler Replacement for Easy Use
    Hey Mike, thanks for reaching out! I mean you can technically install the Curt QuickPin No-Latch Trailer Coupler # C22CR on an A-Frame but you're looking at some pretty heavy modifications and you'll need to hire out a professional welder for this too. For something easier than the standard coupler you currently have, I recommend going with the Demco eZ-Latch # DM14793-81 instead. This is just easier to use altogether, and it can be bolted or welded on to your trailer frame depending...
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  • Which MORryde GooseTech Pin Box Can Replace MORryde Cushioned Pin Box RPB72-1621SHD-TA
    Hey Jimmy! MORryde doesn't have an option with the GooseTech that uses 6 bolts per side. However, the MORryde GooseTech 5th Wheel to Gooseneck Pin Box for 18K+ Trailers w/ Lippert 1621 # MR47MV still has a 24k capacity with 5 bolts per side. As long as you have a GVWR of 18,000+ lbs on your trailer this is the correct model. You will also need safety chains # GY49GR. A lock # IR66FR is available as well if you want to keep it secure. What kind of 5th wheel do you have?
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  • Can I Tow w/ the InfiniteRule Lock for Demco eZ-Latch Trailer Couplers IR66FR Installed?
    Yes, you can so long as your Demco EZ latch coupler is cast like item # DM14040-81 or item # DM37ZR. The InfiniteRule Lock for Demco eZ-Latch Trailer Couplers item # IR66FR works great with these couplers whether they're being towed or parked.
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  • Lock for Demco Hydraulic Brake Actuator
    Hi Frank; I'm sorry to say the # IR66FR is not compatible with your Demco Hydraulic Brake Actuator # DM72VR since it is stamped and not cast. For whatever reason they don't have a different version for that Demco coupler style. You will have to stick with a standard pin lock like # e98888 or get a surround lock like the BulletProof Hitches Extreme Duty Coupler Lock # BPH96VR. I like the surround style since it takes more work for your average thief to defeat it. What kind of trailer do...
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  • Recommended Lock for the Demco eZ-Latch Gooseneck Coupler Adapter
    Hey Connor, there is no integrated lock for the Demco eZ-Latch Gooseneck Coupler # DM73KV but you can use the InfiniteRule Lock for Demco eZ-Latch Trailer Couplers # IR66FR to lock it, no Gooseneck coupler lock necessary. What kind of trailer do you have? If you have any other questions, please feel free to drop a comment and let me know!
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  • Lock for Demco EZ Latch Coupler # DM114041-8
    Hey Alan, yes we do have locks for the Demco EZ latch coupler # DM14040-81 that you referenced with the InfiniteRule Lock part # IR66FR.
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  • Which MORryde GooseTech Fits 2025 Jayco Pinnacle 38KPTS
    Hey Scot! The correct MORryde GooseTech for your 2025 Jayco Pinnacle 38KPTS depends on your pin box bolt pattern and GVWR. If you aren't sure which bolt pattern is on your Jayco you can send me a picture of the sticker on your pin box I can use that to identify it. It looks like the GVWR of your 5th wheel is 17,700 so you need one of the 14K to 18K models. You can choose from the following: -MORryde GooseTech 5th Wheel to Gooseneck Pin Box for 14K to 18K Trailers w/ Lippert 1621 # MR97MV -MORryde...
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  • Can Lock Be Added To Prevent Theft Of Shocker Gooseneck Hitch Coupler?
    Great question! Very smart to lock nice equipment like this. The Shocker Gooseneck Hitch Round # SHK56YR has a built-in spring-loaded Demco eZ-Latch, which works great with most gooseneck locks like the InfiniteRule # IR66FR . If you’re parking in public lots or doing overnight hauls, a coupler lock is a must. What trailer are you planning to install this hitch on?
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  • Will The InfiniteRule Coupler Lock # IR66FR Fit Demco Coupler # DM15000-52?
    Yes, the InfiniteRule Lock # IR66FR is specifically designed to fit Demco eZ-Latch Trailer Couplers like the # DM15000-52.
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  • Does InfiniteRule Lock Fit Demco EZ Latch Coupler
    Hey Joe, thanks for the picture of your coupler! From seeing that I can tell you that the InfiniteRule Lock part # IR66FR that you referenced is a fit for the style of Demco EZ Latch coupler that you have. How do you like the coupler?
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  • Coupler Lock that Fits Head of Demco EZ Latch Actuator DA75
    Hey Michael, we actually have a coupler lock from InfiniteRule that was designed to fit the cast heads of the Demco DA75 actuators like the part # DM33CV with the part # IR66FR. This is the correct length pin to fit the head of the DA75 and prevent the latch from being opened. This also will allow you to lock the coupler to your hitch ball when parked as well.
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  • Shocker Hitch 5th Wheel to Gooseneck Coupler For 2026 Forest River Arctic Wolf 285OPT
    Hey Garrett! The correct Shocker Hitch 5th Wheel to Gooseneck Coupler depends on the pin box you have now. Do you know your pin box bolt pattern? If you don't know which one you have I would be happy to find it for you. You can email me a picture of the sticker on your pin box with the serial number by replying to the email with the link for this page. For example, the # SHK99YR fits Lippert 1621, 0719, and Rhino Box pin boxes. If that is what you have then this will work for your setup....
    view full answer...
  • Recommended Lock For A Demco 2-5/16" EZ Latch Coupler
    You certainly can use the Trimax Coupler lock # TMX47FR with the Demco 2-5/16" Ez latch coupler like the # DM14040-81. The Demco coupler is 2-7/8" wide on the outside so it will undoubtedly fit with the Trimax lock, which is more or less universal. That being said, if you need a lock for the Demco EZ latch, I recommend the InfiniteRule Lock # IR66FR which is made specifically for the 2-5/16" Demco EZ Latch couplers so it will be a perfect fit.
    view full answer...
  • Lock For Demco Trailer Coupler With eZ-Latch
    Thank you for your purchase of the Demco Channel Tongue Trailer Coupler - eZ-Latch. The diameter is 5/16" and the lock that is designed specifically for Demco couplers with the eZ-Latch is the following: - InfiniteRule Lock for Demco eZ-Latch Trailer Couplers # IR66FR
    view full answer...


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Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Michael B
Installed by:
Michael B
Employee Jameson C
Expert Research:
Jameson C
Employee Wilson B
Updated by:
Wilson B
Employee Sabrina W
Written by:
Sabrina W

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