Monster Oil Products Classic Line: Rotor PreviousClassic Line: Piston NextECO Pro Line Classic Line: Rotor Classic Line: Rotor $8.95 The same high quality formula that made the Piston series so successful, the Rotor line is designed for rotary valve maintenance and performance. Type: Select Type Lite RotorHeavy RotorBearing and Linkage Lite Rotor Heavy Rotor Bearing and Linkage Quantity: Add To Cart