These direct-mount chainrings are perfectly compatible with Comet Modular Crank arms. The Megatooth design allows you to transfer all the power without worrying about the chain falling off. All sizes of these converters are made of steel and their range is from 26T to 38T. Specifications Compatibility: Comet cranks Chainring Mount Type: Direct mount Number of Teeth: 30 Material: Steel For 1x drivetrains For drivetrains: Shimano 12S