Different trailer locks protect different connection points. Choose a lock for the part you need to secure, then compare the dimensions on its product page.
| Lock type | What to check | Browse |
|---|---|---|
| Coupler lock | Coupler style, ball size and clearance. Not every lock fits every coupler. | Trailer coupler locks |
| Receiver pin lock | Receiver size, pin diameter and usable locking span. | Hitch receiver locks |
| Lock set | Included lock types, dimensions and keyed-alike options. | Trailer lock sets |
Use the product's fitment details and measurement diagrams to confirm compatibility with your trailer, ball mount and receiver. Material and finish details help you compare outdoor-use requirements. A lock is one part of trailer security and should be used with suitable parking and storage precautions.
For a closed latch with a locking hole, compare the RETRUE adjustable coupler latch lock with a keyless model using the four-digit latch lock fitment guide. To compare body, cylinder and shackle construction, see the trailer coupler lock materials guide.
Need help choosing? See lock support information and the dimensions listed for each product.
Protect your trailer with RETRUE heavy-duty trailer hitch lock and trailer coupler lock solutions. Built with durable steel construction and weather-resistant coatings, our anti theft trailer lock products provide reliable security for RVs, boat trailers, campers, and everyday towing applications.
A trailer coupler lock secures the trailer itself by preventing anyone from connecting it to a tow vehicle, while a trailer hitch lock secures the hitch receiver and hitch-mounted accessories to your vehicle. For complete trailer security, many owners use both types together.
Recommended product: Adjustable Trailer Coupler Lock (RTL003)
Why this product: Its adjustable design fits multiple trailer coupler sizes, making it an excellent all-around security solution for different trailers.
Start by identifying your trailer's coupler size and style. Some locks are designed for specific couplers, while adjustable models fit multiple sizes. Choosing a lock that matches your trailer ensures maximum protection and easier installation.
Recommended product: Keyless Adjustable Trailer Coupler Lock (RTL001)
Why this product: Its adjustable, keyless design fits a wide range of trailer couplers and offers convenient combination access.
Yes. A quality trailer coupler lock prevents thieves from attaching your trailer to another vehicle. While no lock is completely theft-proof, a heavy-duty lock significantly increases the time and effort required, making your trailer a much less attractive target.
Recommended product: Trailer Coupler Ball Lock (RTL005)
Why this product: The ball-style design completely blocks the coupler opening, preventing unauthorized hitching.
If you frequently travel or leave your trailer unattended, using multiple locks provides better protection. Combining a coupler lock, latch lock, and hitch receiver lock creates multiple layers of security.
Recommended product: 4-Piece Trailer Lock Set (RTL222)
Why this product: This complete keyed-alike set secures several vulnerable connection points while allowing you to use one key for all locks.
Yes. Adjustable trailer locks are designed to fit multiple coupler sizes, making them ideal for owners with more than one trailer or fleets with different trailer types.
Recommended product: Adjustable Trailer Coupler Lock (RTL003)
Why this product: Its adjustable locking mechanism accommodates a variety of trailer coupler sizes without sacrificing security.
Large travel trailers, equipment trailers, and heavy-duty utility trailers commonly use a 2-5/16-inch coupler, which requires a lock specifically designed for this size.
Recommended product: 2-5/16" Heavy-Duty Trailer Coupler Lock
Why this product: It is engineered specifically for 2-5/16" couplers, providing a tighter fit and higher level of protection.
For long-term storage, use a heavy-duty coupler lock and park the trailer in a secure location. Locking the coupler prevents unauthorized towing and helps protect your trailer whether it's stored at home, a campground, or a storage facility.
Recommended product: Trailer Coupler Ball Lock (RTL005)
Why this product: Its enclosed ball design effectively blocks the coupler opening during long-term storage.
A trailer tongue lock secures the coupler latch, preventing it from being opened or connected to a hitch ball. It's a compact and effective solution for everyday trailer security.
Recommended product: 1/4" Trailer Coupler Tongue Lock
Why this product: This lock secures the coupler latch directly while remaining compact and easy to install.
High-quality trailer locks are built with corrosion-resistant materials and protective finishes to withstand rain, snow, road salt, and long-term outdoor exposure. Regular cleaning and lubrication can further extend their lifespan.
Recommended product: Keyless Adjustable Trailer Coupler Lock (RTL001)
Why this product: It features durable construction and weather-resistant materials designed for year-round outdoor use.
The best choice depends on your trailer's coupler style, but an adjustable coupler lock is often the most versatile option because it fits multiple trailer types, including RV, boat, cargo, and utility trailers.
Recommended product: Adjustable Trailer Coupler Lock (RTL003)
Why this product: Its universal adjustable design makes it compatible with a wide variety of trailers, offering one solution for multiple towing applications.
