Ns bikes rotary rear hubthese high end mountain bike hubs with thru axle systems will keep the rear end of your frame much more stable each hub is designed to work with 2 drop out systems 135x12mm and 142x12 or 157x12 and 150x12 as two sets of cones are included they are light enough for racing and strong enough to take big slopestyle jumps fully sealed running on 4 bearings and featuring oversized alloy 7075 axles you can be sure they will hold up to any kind of abuse featuresmaterial