bicycle Cassette freewheel11/12 speed card with 9-50T flywheelGear/bike Chain Chain/mountain Rear Derailleur Speed Hanger Mount/direct Mount 6S Steel Tianjin R26 Bicycle Parts Black or Brown18047 8s/9s/10s/11s/12s 32T/36T/40T/42T/46T/50T Silver Gold Mountain Bike Freewheel Cassette Bicycle ...