Designed specifically for Cast Demco EZ Latch couplers for a precise, secure fit Made in USA: Family-run business made with heavy-duty industrial-grade welded steel to be bolt cutter and crowbar proof Helps deter unauthorized hookup and trailer theft during storage or parking High-Security Cobra SideWinder Puck Lock: Designed with advanced pick resistance, limited key blank access, and over 250 million possible key combinations. Uses a multi-plate locking system with anti-picking grooves and a sidebar mechanism to keep the cylinder engaged when locked. Symmetrical key design allows insertion in either direction for easier daily use. Application Use: Ideal for contractors, haulers, RV owners, and utility trailers during storage, parking, or transport 3/16 welded, cold-rolled steel construction with a sand blasted, bright yellow powder coat and a no-nonsense design that fully encompasses the ball head of a Demco EZ Latch coupler. Accepts most "puck" style locks which by design are completely bolt cutter proof. Time, noise, power tools or a cutting torch will be required to defeat our lock design which will eliminate most theft interest. Be sure to compare your coupler to the pictures here and DO NOT buy if it does not match.