104mm BCD 4-bolt chainrings for MTB, Boost, and Fat applications Narrow/Wide tooth design for chain retention on 1x systems 10, 11, or 12 speed compatible Forged and hard anodized AL6061-T6 alloy construction 104mm 4-Bolt 32T 1x AL6061 Black 10/11/12s Narrow/WideUPC/EAN/GTIN: 888571055472