Coupler lock applicable for 1-7/8", 2" and 2-5/16" coupler. -Steel die casting with vivyl cover. Easy Single Action Key Protects Unattended Trailers Design Shields Lock From Tampering Devices Fits most 2" trailer couplers Coupler width (including lip) cannot exceed 3-13/16" Height of coupler lip cannot be greater than 5/16"