Compact-10 Series 8" Dual Diaphragm zinc plated power brake booster. This 8" GM truck brake booster is hand polished before a zinc finish is applied for a top quality finish. The Compact-10 mounting bracket and push rod assembly is a direct fit to your factory firewall. The Compact-10 series boosters are designed to mount closer to the firewall at a more natural angle than a factory style booster. This type of mount gives you the look & brake performance you want out of your truck.