Compared to conventional stainless steel materials, our carbon steel bicycle coupling is more stable and firm, not easy to deform, rust resistant, corrosion resistant and have a longer service life. Easy installation and high safety factor, first attach the towing hitch to your bike, then attach the bicycle trailer with the connecting pin, then you're done The installation of the bicycle towing hitch is very quick and easy. You can install it in minutes. Our bicycle coupling can be attached very well, is not easy to open and does not loosen by itself. It can ensure the highest level of safety when driving. It is constructed of carbon steel material. The length of the product is 5.7cm, and the height is 3cm. Suitable for trailers is suitable for most bicycles such as mountain bikes, folding bikes, normal bicycles and children's trailers, pet trailers, etc. Item Name: Trailer Coupling Material: Carbon Steel Features: Rust-proof, Heavy Duty, Wear-Resistant, High Hardness Size Details: Trailer Coupling: Length: 5.7cm/2.24", Height: 3cm/1.18" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: A: 1 x 90-Degree Trailer Coupling 1 x Buckle B: 1 x 135-Degree Trailer Coupling 1 x Buckle C: 1 x 135-Degree Trailer Coupling 1 x Quick Removal Buckle D: 1 x Trailer Coupling 2 x Buckles