Patented Drop-Stop ® wide-narrow tooth profile for minimised dropped chains Perfect for 1x setups Machined in-house at Wolf Tooth's HQ in Minnesota, USA Beautiful anodised finish Compatibility These rings fit any 120 BCD crankset or 4-bolt spider. For SRAM cranksets you must use the stock M10x.75 bolts with a shoulder on them. These are not standard bolts and Wolf Tooth's bolts will not work with this chainring. Note that only about 3 threads will engage (same with the stock SRAM rings). The only other supplier of these M10 x .75 bolts is Wickwerks if your crankset doesn't already have them. These bolts actually have more threads engaged and will work better than the SRAM ones. 36t is the smallest number of teeth that fits on a 120 BCD. For 1x9, 1x10, 1x11 and 1x12 drivetrains (including SRAM Eagle) Compatible with all 10-, 11-, and 12-speed chains except Shimano 12-speed chains. If using a 9-speed drivetrain use a 10-speed chain (shifts and works well on a 9-speed drivetrain and fits the ring tighter for better chain retention). Chainline - 51mm for 36t and 52mm for 38t (38t is wider for more chainstay clearance)