Description:The bike trailer coupler is made of metal with coating, precision welding technology makes them sturdy and durable, they are not easy to break, rust or corrode, suitable for long-term use.the bike metal attachment connector accessory is easy to install and can be applied to bike, suitable for daily use and family tour use.Please check carefully before purchasing.Specification:Material: MetalColor: BlackBicycle Trailer Coupler Size: 56x29x52mm / 2.20"x1.14"x2.05"(L*W*H)Hole Diameter 1: 23mm / 0.91"(D)Hole Diameter 2: 10mm / 0.39"(D)Hole Diameter 3: 7mm / 0.28"(D)Trailer Coupler Length A: 12mm / 0.47"(L)Trailer Coupler Length B: 45mm / 1.77"(L)Diameter: 17mm / 0.67"(D)Package Includes:2 x Bike Trailer Coupler Attachment.