These premium Sram compatible Direct mount BOOST148 1X Oval chainrings are designed for GXP and Long BB30 spindle cranks. Chainring is dedicated for Boost148 bikes ONLY. Converts a regular Sram crank into a Boost specific setup. (3mm offset) Fits SRAM XX1, XX1 Eagle, X01, X01 Eagle X1, X0, X9, X7, S2210, S1400 and Truvativ AKA cranks. GXP and Long spindle BB30. BOOST148 bikes ONLY. 9, 10, 11 and 12spd Eagle compatible.