The Stay Strong Reactiv disk hubset consists of the Reactiv 10mm alloy fully sealed front hub with alloy female axle and the Reactiv alloy fully sealed rear hub with hollow axle, 6 Pawl, 180 points of engagement and alloy 7075 16T cog. ###section### Product Specs HUB TYPE:Cassette AXLE:Front 20mm / Rear 10mm DRIVER:16t SPOKE HOLES:36 WEIGHT:Front 294g / Rear 413g