This heavy-duty trailer coupler lock offers excellent security for RVs, trailers, and boats, fitting 2 and 2-5/16 inches bulldog couplers. Made of durable carbon steel, it resists tools like crowbars and drills. The powder-coated surface and aluminum alloy lock body avoid rust, while the lock is easy to install and comes with 3 keys for added convenience. | Vevor | | Trailer Lock, Fits 2 & 2-5/16-Inch Bulldog Trailer Couplers, Heavy Duty Hitch Lock with 3 Keys Secures Security | Black | Best Buy