This is a high-performance brake caliper from Wilwood. It features a single piston 2.50" in diameter. The caliper is aluminum finished with an anodized gray coating that looks great.This caliper is designed as a replacement caliper for the GM metric brake caliper and is compatible with 1.04-inch rotors. It is a floating caliper type, which helps to reduce brake drag and improve overall performance. This is a great upgrade for any vehicle that needs improved braking power and responsiveness. Still in original packaging.