The Wiseco Piston Kit for Yamaha RT100 1990-2000 RD200 includes a 52.50mm bore size with a +.020" oversize, suitable for 2-Stroke engines. The kit comes with a manufacturer warranty of 90 days and free shipping for the lower 48 states. Made with forged aluminum alloy, this piston kit is designed for motorcycle street and off-road rides with a displacement of 99 cc. With an average delivery time of 4-5 days, this piston kit is a reliable choice for enhancing engine performance.