ULTRA-HIGH SECURITY TRAILER COUPLER/HITCH LOCK: The straight forward and strong design fits most Pintle Style Coupler as pictured. HEAVY DUTY: This no-nonsense Pintle coupler trailer lock is is constructed of fully welded cold rolled Steel, 1/4" top and bottom plates with a 3/8" lock "mast" which accepts most puck style locksand is bolt cutter, and crowbar proof! . 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. HIGH SECURITY PUCK LOCK: Cobra SideWinder have extreme picking resistance, limited key blank access and over 250 million key code combinations available. Each Cobra SideWinder lock has 10+ combination locking plates each containing multiple anti picking grooves. The locking plates align with a sidebar to keep the inner cylinder engaged with the shell in the locked position. SideWinder locks have a Symmetrical key that will work in either direction, making this a very user-friendly lock. FT. KNOX LOCKS: We are a family run and operated small business with our locks designed and proudly made in the USA. 1/4" top and bottom plates with a 3/8" lock "mast" which accepts most puck style locks . This is a no-nonsense design which will required power tools, noise or a cutting torch to defeat. Please call us if you have any questions. Made in America!!!