CNC machined from 4.5 mm thick, heat treated CRMO. With a Lifetime Guarantee it’s last sprocket you’ll ever need to buy. Keyed for 19mm or 24mm/ 48 splined spindles only. Eliminates a sprocket bolt completely. Guys like Drew Hosselton and Connor Lodes have been on the Mugatu for close to a year and swear it will be their last sprocket on their bike. Now that’s saying a lot!