1. King Pin Locks
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  3. Keyed Unique
  4. Aluminum
MasterLock High Security King Pin Lock

MasterLock High Security King Pin Lock

Item # ML387
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Our Price: $127.16
You Save: $13.97
King Pin Locks
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Shipping Weight: 7 lbs
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Fastest Shipping and Guaranteed Lowest Prices for MasterLock High Security King Pin Lock. Read our customer reviews of Master Lock king pin locks. Call 800-298-8924 for expert service or order your king pin locks part number ML387 by Master Lock online at etrailer.com.
  • All Info
  • Reviews (16)
  • Q & A (3)
  • Photos
  • Why etrailer?

Master Lock King Pin Locks - ML387

  • Keyed Unique
  • Master Lock
  • Aluminum


  • Secures the king pin on fifth wheel trailers, semi-trailers and RVs
  • High grade aluminum provides high security
  • Resistant to bolt cutters
  • Red body alerts that lock is attached

387 Masterlock High Security King Pin Lock

Customer Reviews

MasterLock High Security King Pin Lock - ML387

Average Customer Rating:  4.9 out of 5 stars   (16 Customer Reviews)

- ML387

Nicely engineered, easy to install and remove, handy carrying handle, easy to see your RV is secured - great product! 225894

- ML387

Solid product. Color really helps avoid head collisions when accessing cargo area. 282048

Holding up well. Daunting looks probably wards off plenty of evil doers :-
Mark K - 08/10/2017


- ML387

Love Love Love this company. Every time I order from them, My order has been on time or early. Highly recommend this Company. CLASS A... 792971

- ML387

Solidly built and easy to use as advert ised 756998

- ML387

Probably overkill when parked in the RV storage lot, but I'll feel better while the RV is unattended out at some dispersed camping location. I bought MasterLock because I trust the brand. The unit seems solidly built. It coupled to my king pin without any issues. 613888

- ML387

Great product at a great price. If you got a fifth wheel you don't want stolen, this is the lock for you. The only way anyone is getting this thing off without a key is a locksmith or a cutting torch. This thing is built to the extreme. The collar is almost an inch thick steel and completely encompasses the padlock. 604292

- ML387

Great product to use and is of very high quality. I feel very comfortable securing my trailer with this King Pin lock. My drivers have used this for many situations when we had to drop the trailer in an area to get something fixed so we could get the tractor in a tight spot. 597070

- ML387

We use our lock constantly! We have never had an issue. It is compact, easy to use, and most importantly gives us peace of mind! Great product and highly recommend it! 577079

- ML387

Great item...no way of getting to lock(vandalize) when placed on king pin..Able to leave trailer secured and have mental piece while I'm away around town. 469105

- ML387

It protects mu $125k Toy Hauler. Love it, yes on recommendations . 461042

- ML387

Great well made product, fast delivery arrived on the date that was told it would. Will be great having a peace of mind not worrying about RV when we're not there. Highly recommend this product for anyone with a RV. Thanks for great Service and product. 414876

- ML387

Product works great but has not held up as great against the weather. Handle has pitted pretty bad. It functions fine as long as you keep it lubricated. Would recommend it to anyone who has to store their fifth wheel 398102

- ML387

Lock appears to be robust and the difficulty of defeating it quite high. It was very easy to install and I am hoping that it will act as a great deterrent. 317565

- ML387

Very solid lock that I'm sure will deter anyone from even trying. i was a little surprised that the wrapping around the handle is not rubber; it's more like a sheet of vinyl wrapped around several times. I guess it's ok, but will have to wait to see how durable it is. Overall, my main requirement was for a solid heavy duty lock, and this fits the bill. 314384

- ML387

Received my product and all went well. Except for UPS holding on to it for 2 and 1/2 days then delivering at 8PM at night 230392

- ML387

Just as advertised and easy to use. Pe rfect. 141197


Ask the Experts about this Master Lock King Pin Locks

  • Recommendation For A Gooseneck Trailer Lock
    The MasterLock High Security King Pin Lock, Item # ML387, is not compatible with your Big Tex Gooseneck Trailer. The MasterLock is for fifth wheel trailers and will not work with gooseneck trailers. We do have some gooseneck locks like the the Blaylock EZ Lock Gooseneck Coupler Lock, Item # BLTL-50-40D, that will work if you have a Bulldog, Stallion, Superior, or T.E.M. coupler. If this will not work for you, let me know which coupler you have and I will look for other options.
    view full answer...
  • Will Master Lock 5th Wheel King Pin Lock Fit 2015 Keystone Alpine 3010RE
    Based on my research, the Masterlock High Security King Pin Lock, part # ML387, will work for your trailer. As long as the king pin on your 2015 Keystone Alpine 3010RE is a standard 2 inch diameter king pin, the # ML387 will work well for you. I have attached a review video of this lock for you.
    view full answer...
  • Availability of Keyed-Alike 5th Wheel King Pin Locks
    We can offer you several choices in a 5th wheel king pin lock that can be ordered in multiples that are all keyed alike but Master Lock King Pin Lock # ML387 is not among them. We offer our aluminum King Pin Lock # e98896 and Blaylock offers their aluminum EZ Lock # BLTL-70-40D. Both of these can be ordered in any quantity you need with all locks keyed to the same key. Just select the keyed alike option from the drop-down menu tool and then select your quantity. There is a modest charge...
    view full answer...

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Info for this part was:

Installed by:
Cole B
Updated by:
Sarah W

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