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Master Lock

Master Lock Trailer Hitch Lock, Fits 1-7/8 in., 2 in., and Most 2-5/16 in. Trailer Couplers, Weather Resistant Automotive Hitch Lock with Keys, 377KA

  • Based on 3,616 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Amazon
Arrives Thursday, Apr 2
Order within 16 hours and 7 minutes
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Features

  • Fits 1-7/8 inch (48mm), 2 inch (51mm) and most 2-5/16 inch (59mm) trailer couplers
  • Advanced locking mechanism resists picking and prying
  • Easy to install and remove
  • Aluminum diecast finish resists rust and corrosion
  • Limited Lifetime Warranty provides peace of mind from a brand you can trust.

Description

The Master Lock No. 377KA features a trailer coupler lock, designed to fit 1-7/8 inch (48mm), 2 inch (51mm) and most 2-5/16 inch (59mm) trailer couplers. The advanced locking mechanism provides resistance to picking and prying. The Limited Lifetime Warranty provides peace of mind from a brand you can trust.

Manufacturer: ‎Master Lock


Brand: ‎Master Lock


Model: ‎Trailer Hitch Lock


Item Weight: ‎1.83 pounds


Product Dimensions: ‎5.6 x 4.3 x 2.8 inches


Item model number: ‎377KA


Is Discontinued By Manufacturer: ‎No


Manufacturer Part Number: ‎377KA


Special Features: ‎Weather Resistant


Date First Available: October 3, 2008


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Thursday, Apr 2

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Similar Products

Top Amazon Reviews

    • Easy to use, secure and very sturdy.
Style: Trailer Hitch Lock
Bought my first one 15 years ago and it still works great, you can push it shut in a ratching fashion without even having the key in it. Fits trailers with 1 7/8" , 2" and 2 5/16" ball socket. Bought another for a second trailer. The design would make it difficult to pry it saw off. Much better than the u-bolt over the top design which only locks on one side and could be sawed quickly with a saws all of pryed in the non-locking side. For extra security use one of these and a lock through the latch and it isn't going anywhere. ... show more
Reviewed in the United States on October 28, 2019 by Richard Williams
    • Good Lock !
Style: Trailer Hitch Lock
first lock came without keys. Company sent a new one out, had it in a couple days. No problems , all working good.
Reviewed in the United States on March 24, 2026 by Christopher O Doane
    • Worth every single penny
Style: Trailer Hitch Lock
Amazing product !!!! Works perfectly, great price and as described 👍🏻
Reviewed in the United States on July 16, 2025 by nick_74
    • Camper lock
Style: Trailer Hitch Lock
Great quality
Reviewed in the United States on September 9, 2025 by chris
    • Relatively Inexpensive Trailer Theft Protection
Style: Trailer Hitch Lock
This Item, the Master Lock Trailer Hitch Lock, is my backup lock we utilize on our 27 ft travel trailer. The trailer lock is sturdy, and it does not appear to be easily defeated (hack saw or bolt cutters). Those 2 components were factors in my purchase. If you are on the fence about buying a trailer lock, Let me assure you it is an essential tool in the RV travel world. I would imagine that also applies to boats and other utility type trailers. I could say more...but back to this lock. After purchasing this lock and using it, I switched it out with another lock I purchased. This lock blended in with the front of the trailer, the other one I purchased was a bright red color. So, while I like it, and I still own this lock, it is a backup to the red one that screams to would be thieves "Don't bother". This is fine, works great. ... show more
Reviewed in the United States on September 9, 2023 by The Clark Expedition
    • safe hitch
Style: Trailer Hitch Lock
A great product for the price
Reviewed in the United States on December 28, 2025 by Michael O.
    • Good design
Style: Trailer Hitch Lock
Great design. Probably only honest man lock but appears sound. I would not hit it with a sledge!
Reviewed in the United States on October 4, 2025 by Michael Hirsch
    • Prefer this style to others. Fits well
Style: Trailer Hitch Lock
I like the way this lock works. Fits all my 1 7/8 and 2" trailers
Reviewed in the United States on April 20, 2025 by Richard A Tilley

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