This is a main bearing to fit the BSA unit singles and Bantam, equivalent to part number 24-0732. Will fit lots of other applications, also known as MJ25 or the Triumph part number 70-8003. Crankshaft bearing for the following models:- D/S Ariel 200cc Colt, BSA Bantam (1948-71), C10/C11 (3&4 Speed), C12/C15/B40 Star/Sports, C25/B25 Ball race, Triumph TR25/TR25W 250cc (1967-) Villiers 1H 225cc/2H 250cc.