Requires no sprocket bolt. Instead, it has a hardened Cr Mo steel insert in that matches up to the 48 splines on the crank axle for pure, direct power transfer. Available for 19mm splined axles only. 1/8″ tooth width for use with most freestyle/street & single speed chains. section Product Specs TYPE: Spline Drive
Material: Alloy WEIGHT: 76g/2.65oz