Die cast alloy and CNC machined external cups Composite center sleeve w/ double o-ring seals Oversize stainless cartridge bearings DI2 compatible Compatible with Energy, Gossamer, and Trimax, MegaExo 24mm spindle non-pinch bolt road cranks 68mm ENG MegaExo Alloy 91gUPC/EAN/GTIN: 400310064653