This TH400 Billet Aluminum Direct Drum is manufactured specifically for drag racing. Comes complete with: Billet aluminum piston and 3 Sure Seal sealing rings. Billet aluminum 7075 T6 drum weighs 3.39 lbs. 55% less than the OEM drum. Holds up to 6 frictions with a TCS billet apply piston. Utilizes a 34 element high performance sprag. 1/4″ locking dowels to eliminate inner race movement. Steel sleeve for sealing ring.