Altus FC-M171/M311 Cranksets Chainguard integrated design. Hyperdrive SG-X chainrings. Chainguard model. Item Specifications: Color: Black, Spindle Interface Type: Square Taper JIS, Pedal Spindle: 9/16", Chainring BCD: Riveted, Rings: 48/38/28, BB Included: No, Crank Intended Use: Mountain, Defined Color: Black, Crank Length (mm): 170, Drivetrain Speeds: 7, Drivetrain Speeds: 8, Number of Chainrings: Triple, Chainline/Hub Compatibility: 135/142 MTB Hubs,