IIIPRO hydraulic brakes have 4-piston oil pressure,which having stronger braking force.The brake pads adopt ceramic heat dissipation pads, which have strong heat dissipation and waterproof performance.The control direction is left front right rear, easy to install.suitable for most mountain bikes, electric ebike,fat bike,folding bike. IIIPRO 4 Piston Brake Descriptions: Brand: IIIPRO Part Type: 4-Piston Hydraulic Disc Brake Package Included: Front & Rear Brake Housing Length: 800mm(front)/1550mm(rear) Item Weight:230g(Front) 245g(Rear) Color: Black Control Way: Left Front/Right Rear Clamp Diameter:22.2mm (0.87inch) Adapter Size: 160mm (PM Only) Pads Material:Ceramic Material: Aluminum -Passed German TUV safety certification.