The Shimano MT501 HollowTech II Bottom Bracket fits 68-73mm shells, offering smooth performance and reliable bike gears compatibility. Featuring high-quality seals and English threaded cups, this bottom bracket is designed for HollowTech II chainsets and ensures long-lasting durability. Perfect for upgrading or maintaining your bike in top condition. Buy your bike gears at Halfords, the UK's largest bike accessories retailer.