Our premium E*thirteen (E13) Direct mount Oval chainrings are designed for E*thirteen TRS cranks only. It replaces stock round chainring.Size (Weight):30T (58g)32T (62g)Compatibility: E*thirteen TRS, TRS+ and TRS Race Carbon cranks only. 9, 10, 11 and 12spd Eagle compatible.Materials: CNC machined 7075 Txxx Aluminum. Long-lasting constructionChainline: 49mmMounting: Direct MountOvality: Optimized to each size separately. Range: 10.2-14.4% and Timing of 110.5-116.3° after TDC (top dead center) Patent PendingAdvantages of our special Oval chainrings:Finest design to provide excellent weight to strength ratioOne of a kind special oval shape (Patent Pending)Unique Patent Pending narrow-wide teeth profiles to keep your chain in place for minimum 12 months!Special 3D teeth machining for ultimate mud relief decrease wear and noise dramaticallyDesigned to handle mud and grass with easySuperb quality and great look.You will ride faster using ovals. If you keep using round ring then others will get quicker.Reduces stress on knees and helps to maintain your legs fresher for longer.You will not feel the oval shape at all.