This Tide Down Engineering Hydraulic Disc Brake Caliper fits Tie Down Engineering Eliminator Brakes with Vented Rotor Design. This Caliper with work for both 5 Lug and 6 Lug, 3500lb - 6,000lb Trailer Axles. This Brake Caliper features single piston design, floating brake pads, aluminum casted housing with E-coat finish, b-metal piston with Stainless Steel Piston Cup, Dual Bleeder Valves, and Brass Fittings