CNC machined and drilled sprocket Lightweight steel .10mm Wide foot spreads the loads over a greater surface area than a straight single sprocket and will significantly reduce the risk of the sprocket biting into your alloy freehub splines.5/64″ Teeth fits 1-9 speed chains.16,17 and 18T sizes.Designed to work with Gusset 66C Campag SS convertor.