This direct-mount converter is a perfect match for Afterurner modular cranks. Thanks to the mega-tooth design, you can use all your power without fear of chain drop. All sizes of these converters are steel and range from 26T - 38T. Type Chainrings Color Neutral Series AFTERBURNER, NO SERIES Discipline MTB Compatibility AFTERBURNER modular Bolt Circle Diameter (BCD) DIRECT MOUNT Teeths Number 28, 30, 32, 34, 36, 38 Crankset Type Single Drivetrain Compatibility Shimano 9-11S, Shimano 12S, Sram 10S, Sram XD 11/12S