Bsa is another way of stating english threading; it comes from british standard cycle. English threading on road bikes mean a 68mm wide, 34mm inside diameter shell with reverse threading on the drive side. Its the most common threaded standard employed today. This kit works with 24mm diameter thru-axle cranks, found on shimano, fsa, rotor, among others.Choose between two bearings for the cups. Standard bearings have low drag thanks to hardened-steel races and our ceramic balls. Coated bearings have those same balls installed on coated, hardened-steel races for longer life and less bearing drag.Features:2 threaded cups with bearings.2 dust covers with built-in spacers.Spacer tube.10mm syringe of all round grease.Sticker sheet.