This is a UFP, Unique Functional Products Boat Trailer Disc Brake Caliper Model Number DB-35. This is the Zinc Plated Version that fits 9.75" Rotors only. This UFP Disc Brake Caliper features Stainless Steel Brake Pad Guides, a Hard Chrome Plated Piston, and Stainless Steel Anti Rattle Clips for quiet trailering and braking. UFP brake pads feature anti corrosive materials and reduce overall rotor wear. These Calipers also feature a large, easily accessible Bleeder Screw. This is the Left Hand Side for replacement. We also have the Right Hand available if you are needing a replacement pair. This caliper mounts with (2) Brake Flange mounting bolts, which are included with the Caliper.