Hope oval retainer ringhopes oval retainer ring helps to smooth out your pedalling action and make those extended climbs to the top of the trails less painful also when youre on the way back down again youll enjoy excellent chain retention thanks to its narrowwide tooth profile when used along with a clutch style rear mech you dont need a chainguide so overall weight is reduced and your drivetrain runs quieter and with less drag the oval retainer chainring is cnc machined from 7075 t6