Aupar Gooseneck Trailer Lock for 7-Inch Bottom Plate Coupler — Black welded-steel tube lock, keyed cylinder

Aupar Gooseneck Trailer Lock is a heavy-steel lower tube lock that secures most 7-inch bottom plate couplers—adding a tough, visible barrier to deter theft.

The Aupar gooseneck lock is built to protect gooseneck trailers by locking the lower tube and preventing easy removal from a hitch. Designed with a patented shape that accepts both square and round trailer tubes, it fits the common 7-inch bottom plate couplers used on many popular models. Finished in black and constructed from welded steel plate, this lock is intended to provide a rugged physical obstacle for would-be thieves while remaining simple to install and remove when you need to use the trailer.

How does this lock attach to my gooseneck trailer?

The lock clamps around the trailer's lower gooseneck tube and mates with the 7-inch bottom plate coupler to block detachment. A single keyed cylinder secures the assembly so it cannot be slid or levered off without the key.

• Patented fit for square and round tubes to match common gooseneck profiles.
• Designed specifically for most 7-inch bottom plate couplers, including popular brands.
• Single-piece lower sleeve plus keyed lock for straightforward operation.

Will it stop thieves using common break-in methods?

The Aupar lock increases the time, noise, and effort required to steal a trailer by physically blocking removal at the coupler point. While no device is totally impervious, this model uses heavy steel and solid welding to resist cutting, prying, and quick opportunistic theft.

• Thick steel plate construction reduces vulnerability to hand tools.
• Secure welds prevent easy separation of lock components.
• Visible black finish acts as a deterrent to casual thieves scouting targets.

How easy is it to install and carry day-to-day?

Installation is intentionally simple — the lock slides into place and locks with a single key. Its straightforward design makes removal quick when you need to hitch up, and it’s compact enough to store in a toolbox or trailer compartment.

• Minimal parts: one lower lock sleeve and one keyed lock included in the package.
• Quick-install shape reduces time at the trailer when hooking up or leaving.
• Lightweight enough for practical transport, while still offering strong protection.

What should I check before buying?

Measure your trailer’s gooseneck tube and confirm the bottom plate coupler is a 7-inch model. Aupar recommends verifying fit compatibility prior to purchase to ensure correct sizing and function.

• Confirm you have a 7-inch bottom plate coupler commonly used on many gooseneck trailers.
• Check whether your gooseneck tube is square or round—this lock accepts both profiles.
• Contact Aupar customer support if you’re unsure about fit; they offer assistance and after-sales help.

Who this is for: This gooseneck trailer lock suits owners of agricultural, construction, utility, and toy-hauling trailers that use standard 7-inch bottom plate couplers and who want a robust, easy-to-use deterrent. It’s aimed at users seeking a durable, low-maintenance locking solution that is simple to fit and removes the need for complicated installation. If you haul valuable equipment or frequently leave trailers unattended, the Aupar lock adds a reliable layer of physical security without altering your existing hitch hardware.