5Dev Aluminum Aero Road Chainring 8-Bolt Sram 42T BlackLightweight Aero 1x chainrings for road and gravel Shark Fin tooth shaping reduces chain noise on 1x mullet builds with MTB cassettes Machined in San Diego, CA, from 7075 aluminum SRAM 8 bolt Direct Mount fitment Works with Flat Top and Eagle SRAM as well as Shimano 12 speed chains Please note that the Aero design may not work with T47 BBs and is specifically designed to work with SRAM DUB Bottom Bracket Cups Specifications: model Aero chainring ring