XB PRO Oval Narrow Wide Single Chainring (XBP-CNR02N) is now improved with performance-enhancing chain retention technology and Multi-sizing design(X-COM). The world first product compatible 95% models crank arm. Manufactured from T6-7075 aluminium for superb strength and durability, the Narrow Wide Single Chainring is burly enough for Downhill racers and Dirt Jumpers, yet light enough for Cross-Country and Singlespeed riders.