Trailer Hitch Lock Universal Size - Secure Trailer Couplers

In this review the Master Lock 379ATPY is evaluated as a straightforward, no-frills trailer hitch lock for owners who want basic but reliable theft deterrence. The bottom line: it is for trailer, RV and utility owners who need a simple coupler lock that fits multiple standard sizes and resists casual tampering. The reviewer found the lock easy to use on a 2 in coupler, appreciated the zinc construction for outdoor use, and noted that the advanced locking mechanism gives reasonable protection without an expensive investment.

Key Features

• Universal fit: The lock fits 1-7/8 in, 2 in and most 2-5/16 in couplers so it works across a wide range of trailers without adapters.
• Advanced locking mechanism: Built to resist picking and prying, the lock adds a layer of security beyond simple padlocks.
• Zinc construction: The zinc body resists rust and corrosion for reliable outdoor use on trailers and RVs.
• Includes keys: Comes with two keys so a spare is available for a second user or backup storage.
• Brand warranty: Backed by a limited lifetime warranty, which offers added peace of mind on long-term purchases.

Who It's For

The 379ATPY is best for RV owners, horse trailer users, landscapers and weekend trailer owners who need a durable, easy-to-install coupler lock that fits the most common trailer sizes. It is especially useful when a compact, integrated lock is preferred over larger chain or hitch-pin solutions.

Customers who need high-security, heavy-duty anti-theft hardware for commercial-grade trailers or who require a custom fit for nonstandard couplers should look elsewhere or consider complementary measures, as this design is optimized for general-purpose security rather than maximum resistance to extreme attacks.

Pros & Cons

Pros

• Universal sizing covers most common couplers, reducing compatibility concerns.
• Advanced locking mechanism provides good resistance to picking and prying for typical theft attempts.
• Zinc construction helps prevent rust and corrosion during outdoor storage or travel.
• Includes two keys and a limited lifetime warranty, adding practical value.

Cons

• Some users report fit issues on certain trailer models, so fit should be verified before relying on it exclusively.
• Not intended as a substitute for heavy-duty commercial security systems against determined thieves.

Specifications

Our Verdict

The 379ATPY is a sensible, value-oriented coupler lock for most recreational and utility trailer owners who want straightforward theft deterrence and durable outdoor performance. It covers the most common coupler sizes, resists basic tampering, and comes with two keys and a lifetime warranty, making it a practical buy for noncommercial users.

Frequently Asked Questions

Will this lock fit my 2 in trailer coupler?
Yes, the lock is designed to fit 2 in couplers and is reported to be easy to install on that size.

Is the lock weather resistant for long-term outdoor use?
The zinc construction is designed to resist rust and corrosion, making it suitable for outdoor use on trailers and RVs.

How many keys are included?
The package includes two keys so you have a spare for a second user or backup.