Material:The bike tow hitch is finished in steel with black enamel finish, made to Made of heavy duty iron material, strong and durable, resistant to damage. Corrosion, hard to damage Size:Bicycle trailer hitch 90° Suitable for QR axles and solid axles up to 12 mm (OD = 0.48 inch) Each bicycle trailer comes with a hitch equipped with a connecting pin, the pins can hardly be opened, even after you install them, they are not easy to fall off, which can ensure your baby’s safety The package is delivered; With 2 sets of bike hitches, this additional hitch accessory allows mom and dad’s bikes to be connected to the child trailers As a bonus, when your kids get bored of riding, you can attach it; side of your bike