Narrow wide chainrings compatible with Race Face CINCH system cranks. Direct mounting allows an easy switch between rings and spiders. Compatible with 9, 10, 11, and 12-speed (excluding Shimano 12-speed chains) Narrow Wide tooth profiling ensures consistent chain retention Lockring installed/removed with ISIS BB tool Stiff 4mm plate thickness to transfer loads without flexing Round or Oval: Round Material: Aluminum Chainline/Hub Compatibility: 135/142 MTB Hubs, 170/177 Hubs, 190/197 Hubs, 150/157 DH Hubs, 157 Super Boost Hubs, 141/148 Boost Hubs Direct Mount Type: Direct Mount CINCH Tooth Count: 28t Drivetrain Speeds: 9, 10, 11, 12 Offset: 3mm