Wilwood's PS-1 calipers are compact, lightweight (only .93 lbs.) and combine the strength of cast aluminum construction with a sleek, low-profile design. These calipers utilize two stainless steel deep-cup pistons to minimize heat transfer from the .30 in. thick pad to the brake fluid, while employing high-temperature, square-piston seals to control piston retraction. Internal crossover brake fluid passages eliminate the use of external crossover tubes. They're designed, engineered, and manufactured in the USA.