What are the calipers? Brake calipers are a crucial part of your braking system; many people would say that it's the most important part on any vehicle or trailer. The brake caliper contains the brake pads and pistons. It fits like a clamp around a wheels rotor to stop the wheel from turning. Inside each caliper is a pair of metal plates called brake pads. When you push the brake pedal, brake fluid creates hydraulic pressure on the pistons in the brake caliper, forcing the pads to press against both sides of the brake rotor, squeezing it and thus slowing the wheel by means of friction. These calipers were created by Tie Down Engineering, and are designed to fit all USA-made brake systems. Theyre made entirely of a high-tech alloy to dissipate heat faster than standard cast-iron calipers would. The set comes complete with brake padsOrganic/GalvX Brake Pads matching 11330/11331 & 82084 kits which have been paired with the caliper for ideal performance.