Sea-Dog Brass Plated Coupler Lock - 2 PieceBrass Plated Coupler Lock 2 Piece Designed for theft deterrence, coupler locks also provide an additional level of security to prevent accidental uncoupling while in transit to better protect your trailer. Corrosion resistant brass plated zinc construction. Two piece design for better access in hard to reach places. Fits most coupler sizes. Includes two keys. The two piece interlock is designed to prevent theft and improve security to prevent