Features: Universal Use: The steel hitch fits QR axles and solid axles up to 12mm (OD=0.48in), compatible with Burley bicycle trailers, disc brake and full-suspension models. (Does not fit Breezer style dropouts; Flex connector not included). Premium Material: The bike trailer adapter is made of high-quality steel with a solid construction, powder-coated for durability. Easy Installation: Prevent the trailer's replacement connector from spinning during installation by using an Allen wrench through the pinhole to hold it in place while tightening. Safety: The trailer's replacement connector has no sharp edges, reducing the risk of scratches or injury during use. Trailer attachment only; other accessories shown in the image are not included. Specification: Material: Steel Size: approx. 5.85 x 5.7 x 3 cm / 2.30 x 2.24 x 1.18 in Color: Black and Silver Package Contents: 1 Set x Trailer Attachment