Narrowwide teeth prevent chain drop, updated tooth profile runs quieter \n Durable 4mm thick 7075T6 aluminum with reversible laser etched graphics\n Compatible with 911 speed chains, allowing a 1X set up on most any drivetrain (works with SRAM 12sp, but not Shimano 12sp chains) \n 30T rings are threaded for standard M8x0.75 chainring bolts