Forged AL6061-T6 alloy crank arms for Origin8 Thruster Series modular cranksets SRAM 3-bolt interface for direct mount chainrings and spiders 24mm integrated Chromoly spindle Crank arm tip protectors included with MTB/Boost and Fat 100/120 crank arm sets MTB/Boost 175mm 24mm Intergrated BLK SRAM 3-Bolt Interface