64/104mm BCD 4-bolt chainring sets for MTB, Boost, and Fat applications Shifting ramps and stainless steel pins for smooth shifting 10 or 11 speed compatible Stamped AL2014-T6 alloy construction 64/104mm 4-Bolt 24/38T 2x AL2014 Black 10/11s StandardUPC/EAN/GTIN: 888571055540