Sleek geometry of carbon fiber arms to pair with a Quarq DZero or DFour DUB power meter spider, builds a power meter that can handle the toughest of conditions. Available in lengths from 165 to 177.5 so every rider can achieve their proper fit.Key Features:Compatible with Quarq DZero DUB™ and DFour DUB™ power meter spiders,Requires a SRAM DUB™ bottom bracket,.Specifications:Speeds: 12,BB Compatibility: All SRAM Road DUB BBs,Chainring Size: No rings,Crank arm length: 165mm, 167.5mm, 170mm, 172.5mm, 175mm, 177.5mm,Chainline: n/a,BB Spindle Interface: DUB,Chainring material: No rings,Guard: No Guard,Bolt Circle Diameter (BCD): n/a,Crank arm material: Carbon,Color (Crank arm): Natural carbon.