Aupar Gooseneck Trailer Lock for Most 7-Inch Bottom Plate Couplers, Black — Heavy Steel, Keyed Lower Tube Security

This black Aupar gooseneck lock clamps around the trailer's lower gooseneck tube to add a physical barrier against theft. Designed with a patent-style fit for both square and round tubes, it accommodates widely used 7-inch bottom plate couplers—Bulldog-style couplers included—while remaining quick to install and remove when you need to hitch or unhitch.

How does this lock attach to my trailer and coupler?

The lock slides over the lower gooseneck tube and secures through the coupler area, creating a rigid blockade that interrupts standard towing and coupling maneuvers. Its straightforward construction means you don’t need specialty tools for everyday use.

• Fits most 7-inch bottom plate couplers, including popular Bulldog-style models
• Designed for both round and square gooseneck tubes (patent design)
• Includes one keyed lock for quick attachment and removal
• Installation requires only basic positioning—no drilling or modification

How tough is the Aupar gooseneck lock against theft attempts?

Built from heavy steel plate with solid welds, the lock adds a visible, physical deterrent that increases the time and effort needed to steal a trailer. While no lock is theft-proof, this unit creates a doubled layer of protection by blocking the critical lower coupler area.

• Constructed of heavy steel plate for resistance to cutting and prying
• Solid welding minimizes weak points and joint failures
• Robust black finish helps resist corrosion and wear outdoors
• Physical barrier design discourages opportunistic thieves

Will this lock fit my trailer—what should I check before buying?

Measure the diameter or cross-section of your lower gooseneck tube and compare it to the lock’s fit range. Aupar recommends confirming compatibility prior to purchase; contact the seller if you are uncertain about sizing or coupler style.

• Confirm your trailer uses a 7-inch bottom plate coupler or a compatible style
• Check whether the gooseneck tube is round or square—both shapes are supported
• Measure tube width/diameter where the lock will sit to ensure a snug fit
• Reach out to Aupar for compatibility help if measurements are unclear

How easy is it to use day-to-day and what’s included?

The lock’s simple structure keeps daily operation quick: place the unit over the lower tube, align with the coupler, and secure the keyed lock. The package is compact and contains everything you need to start using it right away.

• Package contains one lower gooseneck tube lock and one key-operated lock
• Tool-free installation for routine removal and reattachment
• Low-maintenance finish designed for outdoor exposure
• Keyed lock provides straightforward access control for owners

Who is this for: The Aupar Gooseneck Trailer Lock is aimed at trailer owners who tow with gooseneck couplers and want a robust, easy-to-use deterrent for parked trailers. It’s especially useful for fleet operators, contractors, and recreational trailer owners who need a practical anti-theft solution compatible with common 7-inch bottom plate couplers. If you’re looking for a durable secondary protection method that’s quick to fit and built to withstand real-world conditions, this lock is a strong option.