The Shimano Deore XT BB-MT801 Bottom Bracket is designed for Shimano's HollowTech II two-piece mountain bike cranksets. The MT801 bottom bracket benefits from technology already in place on the flagship XTR edition, and the trickle down means this bottom bracket is lighter and has less bearing drag than the previous XT model. Not only that, there's improved durability via updated seals to ensure mud and grime are kept out. Features: This version is for English-threaded bottom brackets. Shimano XT-level bottom bracket that benefits from XTR-level trickle down For use with Shimano HollowTech II mountain bike cranksets with a 24mm spindle Small ball bearings improve rotation Improved seals to keep the elements out English-threaded for 68mm/73mm width bottom bracket shells Specifications: Frame Interface: BSA/English Threaded Spindle Interface: 24mm (Shimano Hollowtech II) Bottom Bracket Shell ID: 1.37 Shell Width: 68mm, 73mm Color: Black Weight: 84g