The Vevor trailer lock is a heavy-duty coupler lock designed to fit 2-5/16" flanged air flow couplers on trailers, RVs, and boats. Its carbon steel construction and thick wall design help resist prying, drilling, and other theft attempts. The lock features a powder-coated finish, aluminum alloy lock body, and dust cap for added weather resistance. It installs quickly in under 30 seconds and includes 3 keys for convenience. This lock also allows security chains to be secured inside the assembly.