These rings fit Shimano XT M8000 and SLX M7000 1x or 2x cranksets. Use standard Shimano XT M8000 or SLX M7000 chainring bolts only These can be installed on XTR 9000 series cranks, but you need to use the bolt caps included with the crankset and need to be cut approximately 1mm from the threaded boss of each bolt cap (too long and not install). Do not tighten the ring.) Wolf Tooth patented Drop-StopA wide/narrow tooth shape for ultimate chain retention and mud disbursement for 1x9, 1x10, 1x11, 1x12 drivetrain compatible with all 10, 11, and 12 speed chains except for Shimano 12 speed chains (including SRAM Eagle) If you want to use 9 speed drivetrain, use 10 speed chains (shift well with 9 speed drivetrain and tighten the ring to increase chain retention). Chainline - 49mm Boost Crankset Chainline - 52mm Genuine Chainring Bolts Required Wolf Tooth Chainring Bolt Size Vary 10% egg rate and 112 timing after TDC (top dead point) the maximum diameter is 2T larger than the size you order (so make sure you have enough chainstays clearance! )