Wolf Tooth Elliptical Direct Mount Chainring - 30t, SRAM Direct Mount, Drop-Stop, For SRAM 3-Bolt Cranksets, 6mm Offset, BlackDesigned to fit SRAM cranksets with removable spiders. Its proprietary design has an ovality of 10% and a timing of 112 degrees after top dead center which provide the beneifits of an oval ring such as greater rear wheel traction without the traditional downsides of oval rings. Product Details: Compatible with all 10 , 11 , and 12 speed chains, with the exception of Shimano 12 speed chains Drop Stop chainrings are designed for use with 1x9, 1x10, 1x11