1. Trailer Coupler Locks
  2. Master Lock
  3. Latch Lock
  4. Keyed Unique
  5. 7/8 Inch Span
  6. Universal Application Lock
7/8" Wide Trailer Coupler Latch Lock by Master Lock

7/8" Wide Trailer Coupler Latch Lock by Master Lock

Item # 2878DAT
lowest price pledge
Retail:$16.65
Our Price: $9.92
You Save: 40%
Trailer Coupler Locks
Orders above $50 qualify for Free Shipping
Shipping Weight: 0.32 lbs
Quantity: 
In Stock
Master Lock 7/8 Inch Wide Trailer Coupler Latch Lock
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

Customer Photos

Videos

Lowest Prices for the best trailer coupler locks from Master Lock. 7/8" Wide Trailer Coupler Latch Lock by Master Lock part number 2878DAT can be ordered online at etrailer.com or call 800-298-8924 for expert service.
  • All Info
  • Reviews (29)
  • Q & A (7)
  • Videos (1)
  • Photos
  • Why etrailer?

Master Lock Trailer Coupler Locks - 2878DAT

  • Master Lock
  • Latch Lock
  • Keyed Unique
  • 7/8 Inch Span
  • Universal Application Lock


  • 7/8" Shackle fits most popular trailer coupler latch widths
  • Covered keyway resists moisture, dirt, and corrosion
  • Hardened steel construction
  • Removable Python cylinder
  • Ergonomic handle for easy installation
  • Limited lifetime warranty


2878DAT - 7/8" Wide Trailer Coupler Latch Lock by Master Lock





Video of 7/8" Wide Trailer Coupler Latch Lock by Master Lock

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Master Lock Trailer Coupler Locks - Latch Lock - 2878DAT Review

We have here a 7/8 inch wide trailer coupler latch lock. This is a lock for the latch of your coupler and we are going to show you how it works, it is a pretty simple device. Basically you have the key to unlock it and then we will show you how to install it. It has a nice weather tight cover, you turn the key about 180 degrees and the pin comes apart and it is ready to install on your coupler. We have your regular variety latch style coupler here and we will show you how it works. The lock wraps around, you put the pin in and turn the key, put the cover back on and your trailer is secure. A few finer points about this lock is that the body itself has a nice rubber grip surrounding it which makes it easier to use and grab. You have armor on the outside which is covered in plastic so it will not scratch up your new trailer. It could be important on galvanized trailers because you do not want to beat it up and start rusting and cracking. What is also nice is the key itself. It is not a special key, if you take it to the locksmith you can get a copy made. There you have it for part # 2878DAT, from MasterLock, the 7/8 inch wide coupler latch lock.


Customer Reviews

7/8" Wide Trailer Coupler Latch Lock by Master Lock - 2878DAT

Average Customer Rating:  4.7 out of 5 stars   (29 Customer Reviews)


- 2878DAT
by:

My previous coupler locks have been the type that requires turning the key and screw the lock closed. This plunger design is simpler & faster to use. 900940



- 2878DAT
by: 08/21/2020

866137



- 2878DAT
by:

It feels solid, seems to work well so far, my only complaint is that the key hole is taller than the key is and so its annoying trying to get the key started but I think its something I can get used to with time 858044



- 2878DAT
by:

use when traveling peace of mind, hitch won't come off going down road and trailer will not be stolen while not in vehicle 822025



- 2878DAT
by:

Pretty self explanatory but it’s a nice lock. You have to use the key to lock it as well as unlock it. Don’t just snap the pin closed thinking you’ve locked it. Worked great on my harbor freight trailer build. Feels solid. 792082



- 2878DAT
by:

Your product works moderately well, although it bent slightly 784182



- 2878DAT
by:

Nice lock, Don't know what else to say. Fits, works, seems well made 708401



- 2878DAT
by:

Nice and compact. They have stepped up their game. Product has improved over their past products. 705305



- 2878DAT
by:

I use it to secure the latch on a boat trailer. Works exactly as advertised. 655011



- 2878DAT
by:

My trailer’s hitch clip tends to bounce loose on dirt roads. Not only does this unit prevent that, but also dissuades would-be trailer thieves. I’m very happy with the lock. 615306


Comments
It’s still working well a year later.
Eric - 03/30/2020

71993

- 2878DAT
by:

Just a normal hitch lock works for what I need it for! 521800



- 2878DAT
by:

Nice quality lock. It does have a nice thick plastic outer coating. Protects against scratching your trailer and scratching the lock itself. 513726



- 2878DAT
by:

I like the simplicity and weather resistant design of this latch lock. It seems to me to be at least as secure as a pad lock. Being a Master is a plus. 490951



- 2878DAT
by:

My items came shipped timely as promised, and all met my expectations exactly as I needed! 485054



- 2878DAT
by:

Excellent lock. Just what I was looking for. It’s well sealed to prevent water from getting in and freezing. 468979



- 2878DAT
by:

Terrific product. Secure. Easy to use. When not in use, it is easy to stow in small spaces. 466108



- 2878DAT
by:

Works great to lock trailer while hooked to vehicle. 364660



- 2878DAT
by:

I received the package earlier than expected. Good communication and follow up on orders. Will order again. best price on lock. 342245



- 2878DAT
by:

I received the package earlier than expected. Good communication and follow up on orders. Will order again. 342244



- 2878DAT
by:

What can I say, it’s a Master lock. Well-built smooth operation and it does exactly what it was designed to do! 267139



- 2878DAT
by:

just what i needed a lock that you can tether to the trailer tongue so that you do not lose it 264376



- 2878DAT
by:

ty the time and the item where perfect . Wish had 4 G phone I`m still old school with a flip phone :( I would send pictures , again ty for product. the carpet worked fine as the lock was great. The bow roller fits great. the swivel trailer jack fits great and man what a relief to be able to jack it up with it . I was using car jack to unhitch the boat . Need it badly , TY!!!!!!!!!!!! 259030



- 2878DAT
by:

I have a 2-5/16 coupling and the latch is 7/8 inch wide. So I went thru 3 locks before I found this one and like it the best. 218758



- 2878DAT
by:

Super fast delivery. 161859



- 2878DAT
by:

I really like the design of the lock, easy to put on and off. Seems like a good build and should get my money's worth out of it. 155340


25
29
Show More Reviews

Ask the Experts about this Master Lock Trailer Coupler Locks

  • Dimensions Of Master Lock Trailer Coupler Latch Lock
    I pulled one of the Master Lock Wide trailer Coupler Latch Locks, part # 2878DAT from our warehouse to measure for you. As the enclosed photo shows the inside dimension from the barrel to the lock arm measures 7/8 inches and the depth of the lock is 1-1/4 inches. I have attached a link to a product review video for this lock you can check out.
    view full answer...
  • Recommended Trailer Coupler Latch Lock Keyed Alike
    I reached out to my contact at Master Lock, and the 7/8" Wide Trailer Coupler Latch Lock # 2878DAT are keyed at random and do not have the ability to be keyed alike. For a similar option you can use our etrailer.com # e98890 which can be keyed alike. Alternatively, you may be interested in the Fastway Universal Trailer Coupler Lock for 1-7/8", 2" and 2-5/16" Couplers # DT25013KA which can also be keyed alike and add even more security. I've attached a video review to assist.
    view full answer...
  • Pin Width of Masterlock Trailer Coupler Latch Lock # 2878DAT
    Yes, the width of the pin on the 7/8" Wide Trailer Coupler Latch Lock # 2878DAT that you referenced is 1/4 inch.
    view full answer...
  • Will Master Lock Coupler Latch Lock 2878DAT Fit a Fulton 2-5/16 Inch Trailer Coupler
    Provided that the hole in the latch on your Fulton coupler is 1/4 inch or larger and the width of the latch is less than 7/8 inches then lock # 2878DAT will fit. It has been my experience that Fulton couplers for 2-5/16 balls do match this description. I have linked a video review of this lock for you.
    view full answer...
  • What Material is the Trailer Coupler Latch Lock # 2878DAT Made From
    The 7/8" Wide Trailer Coupler Latch Lock # 2878DAT is made of hardened steel. As far as how easy it is to defeat, ultimately any lock can be defeated given enough time and the right tools. Since there is no gauge of how "breakeable" a specific lock is, we recommend making your setup look intimidating to deter would-be thieves. If you are wanting to deter theft of your trailer when it is coupled then the Bulldog # BD580404 is a great option because it has a coupler lock and a ball...
    view full answer...
  • Trailer Coupler Latch Lock with 1 Inch Pin Span
    Master Lock has an adjustable latch lock, # 2847DAT that has presets for either a 1 inch span or a 2 inch span. We also have some that are 7/8 inch spans which is 1/8 of an inch more than a 3/4. We have # e98890, # 2878DAT, and # e98889. I have linked some video reviews of these locks for you.
    view full answer...
  • Trailer Coupler Latch Lock with a 1/4 Inch Diameter Pin Longer than 3/4 Inches
    We have several latch locks that have longer pins you could use. Master Lock Adjustable Trailer Coupler Lock - Stainless Steel Item # 2847DAT has an adjustable span of 9/16" to 2-3/4". Stainless Steel Trailer Coupler Lock # e98890 has a span of 7/8" as does lock # 2878DAT. I have linked videos of these locks for you.
    view full answer...




  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality trailer coupler locks for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate trailer coupler lock information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Expert Research:
Michael H
Expert Research:
Jameson C
Expert Research:
Jeffrey L
Updated by:
Hannah L

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time.