8" diameter; Includes mounting brackets Chevrolet full size cars; Zinc plated New 8" Dual Diaphragm zinc plated power brake booster. This 8" power booster is hand polished before a yellow zinc finish is applied for a top quality finish. The top quality power Chevrolet brake booster is designed mount directly to your factory firewall. New unit not remanufactured Includes brackets and pushrod .