The BSD Back Street Pro Hub is their latest street ready hub, built around their own custom driver that features a skip free mechanism all while maintaining a compact sized shell. Built with a 6061-T6 aluminium hub shell that's paired with a 14mm 4140 heat-treated chromoly axle & 4130 chromoly wheelnuts. It features a bombproof 14mm female bolts, chromoly cones, a massive female axle & hefty 6903 bearings that run smooth. section Product Specs HUB TYPE: Cassette AXLE: Female Bolts DRIVER: 9t DRIVE SIDE: Left Side Drive SPOKE HOLES: 36h WEIGHT: 484g (1.07lbs)