The Cylinder Pump Universal Motorcycle 7/8" 22mm Hydraulic Brake Clutch Master Cylinder Reservoir Lever, when purchased in a red set, is designed to be a comprehensive fit for WR YZ RM motocross rear brake pumps. This master cylinder is made to provide a strong and reliable hydraulic linkage for your motorcycle's brakes, ensuring optimal performance and safety. The cylindrical shape of the reservoir lever ensures a perfect fit and a smooth operating experience, while the 22mm internal diameter caters to the specific requirements of WR YZ RM motorcycle platforms. With its robust and durable construction, this master cylinder is built to withstand the rigors of motocross riding and can be easily installed using the supplied hardware, making it a convenient and effective solution for your motorcycle's braking needs.