Braking - Power Brake Combos - Universal - Tuff Stuff Performance - Brake Booster w/Master Cylinder Univ. 7 in. 1 1/8 in. Bore Single Diaphragm w/PN[2071] Dual Rsvr. Master Cyl. Incl. 3/8 in.-16 Mtg. Studs/Hardware Gold Zinc 2121NB