Extralight! The Stronglight CT2 chainrings are made from 7075 T6 aluminum and feature CT2 technology (Ceramic top layer impregnated with Teflon). Ceramic hardens the surface for longer life and Teflon reduces the chain's friction coefficient by over 80%. The Teflon coating lowers overall friction, which means less need for lubrication and optimized indexation between chainrings. These chainrings combine the following features: wear resistance, light weight, precision shifting and efficiency. 9/10 speed compatible. 35 to 76 grams.