Upgrade your power brake car to a 9 in. slim line power booster and a 1 in. dual bore master cylinder with our quick install kit. This kit allows you to upgrade your factory power brake car in no time. A great kit with a factory look and easy installation. Master Cylinder Bore Size: 1 in, Bowl Design: Dual Bowl, Master Cylinder Material: Cast Iron, Master Cylinder Finish: Natural, Reservoir Included: Yes, Reservoir Material: Cast Iron, Master Cylinder Cap Included: Yes, Brake Booster Type: Single Diaphragm, Brake Booster Diameter (in): 9 Booster Material: Steel, Brake Booster Finish: Black, Brake Pedal Rod Extension Included: Yes, Mounting Hardware Included: Uses Original, Quantity: Kit.