TH400 Aluminum Direct Drum with Extra Large Sprag. Ideal for Pro-Street, Pro-Mods and Top Sportsman. Drum is made from 7075 T6 billet aluminum. Billet aluminum piston. Holds up to 6 frictions. 1/4″ locking dowels have been inserted to stop inner race movement. Steel sleeve for sealing ring. 3 – Sure sealing rings. 5 – intermediate frictions, steels and pressure plate. X-large 36 element sprag. Drum & sprag weighs 6.13 lbs and is 45% lighter than the O.E.M. assembly.