Take your Razor build to the next level by stepping your brake game up one extra notch above the rest with the 4 piston brake kit. 4 Pistons means larger pad to rotor contact patch, better clamping pressure and better heat dissipation. With the high power and speeds achievable with our ultimate kits, stopping power is incredibly important. This 4 PISTON Hydraulic Brake Kit is 100% bolt on ready for the MX, SX and RSF models and is the easiest way to level up your build... and it's safety! Brake Rotors, caliper mounts and all necessary hardware are included with the kit. Compatibility Razor MX500, MX650, SX500, RSF650 ETM3000 / ETM5000 (rotors for razor only) Mototec 1000w Pro Dirt Bike (rotors for razors only) *Requires OEM rear brake caliper bracket Mototec 1500w / 1600w Pro Dirt Bike *Requires OEM rear brake caliper bracket Funbikes MXR 1300w / 1500w Dirt Bike *Requires OEM rear brake caliper bracket Apollo RXF 1000w / 1300w Dirt Bike *Requires OEM rear brake caliper bracket Warning! Do not use with out fully inspecting brakes before every ride. Install both brakes, do not use only one of the two brakes provided, doing so will result in overheating and catastrophic failure. Your safety is your responsibility! Make sure your vehicles brake system is working properly and is able to stop before departing!