Zinc 8" Dual Diaphragm Brake Booster.  This booster is brand new, not rebuilt like other models!  This booster is universal and bolts up to most street rods, hot rods, and other vehicles with no problem.  This is a great upgrade from a single diaphragm booster.  Dual diaphragm boosters offer 19% better stopping power over the single.  You can get one here for a fraction of the price.  This is a safe and inexpensive way to upgrade both the safety and the look of your ride.