These chainrings are for Shimano direct mount cranks. The Wolf Tooth chainrings feature our patented Drop-Stop® design for the best wear life, chain retention and mud clearance.Compatibility:- Shimano XTR M9100, XT M8100, SLX M7100, and Deore M6100 series 12 speed cranksets.- Super boost cranksets -models M8120, M8130, M7120 and M7130 - use the Boost chainring. These Super Boost cranksets have a longer spindle and do not use the Super Boost chainring. These cranks and ring should ONLY be used on bikes with Super Boost rear hub spacing (157mm)- Boost cranksets - models M9100, M8100, M7100, MT610 - will use a Boost ring with Boost rear hub spacing (148mm) and a Super Boost ring with - Super Boost rear hub spacing (157mm). Specifications:- Weight: 32t, 66g- Material: 7075-T6 aluminum