The Absolute Black Raceface Cinch Direct Mount Boost Oval Chainring are designed for CINCH system RaceFace uses to mount chainring directly to the crank. This version is for BOOST 148 specific bikes and FAT BIKES (when reversed). Absolute Black Raceface Cinch Direct Mount Boost Oval Chainring Features Finest design to provide excellent weight to strength ratio One 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 dramatically  Designed to handle mud and grass with easy Superb 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.