Features: Universal Use: The steel hitch fits QR axles and solid axles up to 12mm (OD=0.48in), works with Burley bicycle trailers, disc brake and full-suspension models. (NOT fit for Breezer style dropouts; Flex connector NOT included). Premium Material: Bike Trailers Adapter is made of high-quality steel. It has a solid construction, coated with powder paint and into your bike even if has no trailers. Easily Install: Make sure your trailer's replacement connector doesn't spin while tightening, and throw an Allen wrench through the pinhole, hold it in position while tightening. Safety: This trailer's replacement connector doesn't have sharp edges, so it will not scratch your hand and will not hurt your children, please don't any worry when using it. Trailers Attachment only,other accessories demo in the picture is not included Specification: Material: Steel Size: app.5.85x5.7x3cm/2.30x2.24x1.18in Color: Black and Silver Quantity: 1 Set Note: No retail package. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you Package Contents: 1 Set x Trailers Attachment