Close-up of a black trailer tongue with an Interstate Trailer Defender coupler lock and safety chains attached

Protect Your Trailer with the Trailer Defender® Heavy Duty Coupler Lock

Trailer theft is a real problem. Whether you're parked at a job site or outside your home, trailers are becoming more common targets for break-ins because they’re loaded with valuable tools, equipment, or other cargo. The Trailer Defender® High Security Coupler Lock from TrailersPlus is designed to keep your trailer and cargo safe.

Safety feature layout of Trailer Defender

What Makes the Trailer Defender® So Effective?

  • Available sizes for both 2" and 2-5/16" Couplers: Designed to work with the most common coupler sizes, we have options for both 2” and 2-5/16” couplers.
  • Built Like a Tank: The entire lock is wrapped in ¼” thick steel, making it nearly tamper-proof from all angles. Whether faced with cutting tools, crowbars, or tough outdoor conditions, our trailer lock stands up to the challenge and provides long-lasting protection for your trailer.
  • 360° Tamper-Proof Design: The lock’s tamper-proof design ensures that it is resistant to attacks from any angle. Whether it's cutting tools, crowbars, or other forced-entry attempts, our lock stands up to the test, providing round-the-clock security for your trailer.
  • High-Security Puck Lock: One of the highest security padlocks available is the hockey puck cambar lock, and it’s included in the Trailer Defender®. These locks are surface mounted, and do not look like standard padlocks. Instead, they appear to be a thick disk mounted over two overlapping plates. Hockey puck padlocks are extremely secure, because they have no exposed shackles. This prevents damage from pry bars or bolt cutters.
  • Secures Safety Chains: Designed with convenience in mind, this lock not only secures your trailer but also locks down your safety chains. Prevent thieves from hooking up your trailer by safeguarding both the coupler and safety chains in one go.
  • Proudly Made in the USA: We take pride in designing and manufacturing our locks right here in the USA. Our rigorous production standards ensure that every lock is crafted with precision and built to last, offering you unparalleled security and peace of mind.
Installation steps of Trailer Defender

Why You Need This Lock

Leaving your trailer unattended even for just a few hours can be risky, as it’s often filled with thousands of dollars in tools and materials. If you work in construction or landscaping, we recommend purchasing both the 2-5/16" Trailer Defender® and an adjustable coupler lock. You can use one the Trailer Defender® for quick drop offs, and the adjustable for when your trailer will be parked for long periods of time so you can remove the coupler and lock it. The Trailer Defender® makes it way harder for thieves to take off with your investment, giving you extra peace of mind.

Protect your investment with the Trailer Defender® High Security Coupler Lock. It’s an affordable way to keep your trailer safe, and it’s backed by a guarantee that shows we’re serious about security. Visit one of our 80+ locations across the United States and pick up a Trailer Defender® High Security Coupler Lock today!

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TrailersPlus

TrailersPlus is your one-stop destination for trailer sales, parts, and service. With more than 92 locations across the country and over 11900 trailers available nationwide, we are the largest independent trailer dealership in the USA.

All specifications and measurements are subject to change. Trailer dimensions, weights and measurements will vary due to manufacturing and production changes. Please verify the actual measurements of any unit prior to purchasing it. Each unit listed for sale is a specific unit at the specific location, subject to prior sale, all prices valid until 06/20/2026. The trailer photo displayed may be an example only. Pricing throughout the web site does not include any options that may have been installed at the dealership. We impose a surcharge on credit cards that is not greater than our cost of acceptance. Please see the dealer for details. Some trailers shown with optional equipment. See the actual trailer for complete accuracy of features, options & pricing. The trailer pictures on this site may not match your vehicle exactly; however, it will match as closely as possible. Some trailer images shown are stock photos and may not reflect your exact choice of vehicle, color, trim and specification. Not responsible for pricing or typographical errors.

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