1Wide Application: Replacement for GY6 50cc 139QMB Based Engine, replacement for Kinroad, replacement for Twister Hammerhead, replacement for Carter Talon and much more models. 2Copper Core Roller: The roller shell is made of nylon material with excellent high temperature and wear resistant, and the 6.5 gram weight will bring you balanced performance. 3Red Variator Slides: The racing variator slides has been already installed, comes with red color and made of the same nylon as the roller weights, abrasion resistant and have a long life. 4Heat Sinking Variator Face: Specially designed for better operation and heat dissipation; the roller grooves design can improve the accelerating time and prevent too much loss on the engine torque value. 5Hardening Ramp Plate: The variator ramp plate adopts surface hardening treatment which can make your variator support more power. And the main metal parts have been processed by anti rust treatment for maximum durability.