The Straightline Performance Polaris RMK, SKS, and Assault 850 Single Pipe Calibration Clutch Kit is engineered specifically for machines equipped with a Straightline Performance Single Pipe exhaust system and operating between sea level and 3,000 feet elevation. Featuring Straightline's fully adjustable weight kit, two custom-calibrated clutch springs, and a custom-designed helix, this package delivers stronger acceleration, improved throttle response, faster backshift, and exceptional deep snow performance. Note: Straightline Performance Single Pipe sold separately.