Bicycle Trailer Coupler Hitch Black Universal Cycling Adapter Accessories Rear Replacement Axle Hitch Attachment for Child Pet

Material: The bicycle trailer hook attachment is made of steel, with a black enamel coating, and is made of heavy-duty iron material. It is sturdy, durable, corrosion-resistant, and not easily damaged. The nut fixed inside is 22mm. Each bicycle trailer coupling is equipped with connecting pins, which are difficult to open and once installed, they are not easily detached, ensuring the safety of the baby. The set comes with 2 sets of bicycle trailer couplers, and with this additional trailer coupler accessory, both mom and dad's bicycles can be connected to their child's trailer. The additional benefit is that when your child gets tired from riding, you can tie them to the side of your bike. Specifications: Bicycle rear axle fixing hole diameter: 11 millimeters Fixed hole diameter for connecting trailer: 7 millimeters The diameter of the concave area where the shaft nut is screwed in: 21 millimeters