Forged & CNC machined 7075 series aluminium alloy crank arms Unique expanding spline/arm interface Versatile Spline mount for chainring/spider 30mm oversized axle Different axle length options available to accommodate most bikes from XC, DH & FAT bikes 9, 10 & 11 speed compatible Weight: 641g (arms, axle & 34 tooth spiderless ring)