Ultra-High Security Coupler/Hitch Trailer Lock: This strong and straightforward trailer coupler/hitch lock is designed to secure the common bumper pull trailer. Heavy Duty Trailer Security: This no-nonsense coupler/hitch trailer lock is constructed of 3/16" fully welded cold rolled steel and is bolt cutter and crowbar proof! The surround hasp application accepts most "puck" style locks and provides additional safety and security. (Puck lock not included) Bright Yellow Powder Coat Finish: We believe in presenting a hard target that is why we use a bright yellow powder coat to warn off would be thieves. Coupler Fit: Make sure to double check your trailer coupler/hitch. This lock only fits the coupler/hitches pictured. Ft. Knox Locks: We are a family run and operated small business with our locks designed and proudly made in the USA. Constructed of 3/16" fully welded cold rolled steel, with welded hinges and hinge pins. The surround hasp application accepts all standard "puck" style locks and provides additional safety and security. Time, noise, power tools or a cutting torch will be required to defeat our lock design which will eliminate most theft interest. We believe in presenting a “hard target” that is why this high-quality durable coupler lock has a heavy yellow powder coat finish, which screams "stay away."