About this item The bicycle hook washer is a car hook-proof washer that can firmly lock the bicycle wheel and is easy to install and use Size: 25 mm / 0.98 inches long, 17 mm / 0.66 inches wide, inner diameter includes M8 and M10 Made of high-quality steel, high hardness, heat-treated, very strong and practical, long service life Suitable for road bikes, mountain bikes, folding bikes, flat bikes, etc Listing content: 6 pieces of M8 bicycle hook washers and 6 pieces of M10 bicycle hook washers