Wilwood Disc Brake Kit & Power Booster. Wilwood Red Dual Piston Calipers. Wilwood Booster Conversion Kit 1" Bore E Coat Black Master Cylinder. Why Wilwood?. Forged billet aluminum bodies, stainless steel pistons, and competition style high-temperature seals put and end to the rust, bore pitting, and seal failures that plague the OE caliper design.