The lightest and most refined solution for Cannondale Hollowgram cranks, period Hollowgram spiderless chainrings allow for flawless 1x9/10/11 drivetrain setup 5.7mm offset provides better chainline than other brands Compatible with Cannondale Hollowgram Si, SiSL, SiSL2 and newest F-Si Narrow/Wide tooth profile helps prevent dropped chains Oval construction maximizes pedal stroke and torque transfer 7075 Aluminum construction Hollowgram 32T 7075AL Black 1/9/10/11/12sp Narrow/Wide