One of a kind special oval shape that helps you climb easier and faster Designed for Rotor REX cranks with their original 1X spider Lighter and stiffer than the original Rotor chainring One optimized mounting position means less guess work and more performance Reduces stress on knees and helps to maintain your legs fresher for longer 76mm 4-bolt 34T 7075AL Black 1/9/10/11/12sp Narrow/Wide ...