The Shimano MT800 Threaded Bottom Bracket is designed to work with the 24 mm spindles found on Hollow Tech II cranks like the Deore XT M8000. It borrows the smaller bearing design from the XTR and Dura Ace bottom brackets for less drag and better sealing.
Compatible with 68 mm and 73 mm English-threaded bottom bracket shells. Includes two 2.5 mm spacers and installation adapter for bottom bracket tools designed for standard 44 mm external diameter cups.
A guide to bottom bracket standards.