CNC machined from 7075 Aluminum in the USA, Requires no sprocket bolt. Instead, it has a hardened CrMo steel insert in that matches up to the 48 splines on the crank axle for pure, direct power transfer. Available for 22mm splined axles only .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; } ###section### Product Specs TYPE: Spline Drive MATERIAL: Alloy WEIGHT: 78g/2.75oz