The Absolute Black GXP/Long spindle BB30 Chainring mounts to any GXP crank and adapts it to a Boost 148 chainline. Oval chainrings have been shown to improve traction and reduce leg fatigue. Ideal for 1x 9/10/11 system and single speeds. Machined from 7075 Aluminum. If used on a 1 x 9 system, a 10 speed chain must be used. Features GXP/Long spindle BB30 Chainring mounts to any GXP crank and adapts it to a Boost 148 chainline Oval chainrings have been shown to improve traction and reduce leg fatigue Ideal for 1x 9/10/11 system and single speeds 11 percent ovality Compatibility: SRAM XX1, X01, X0, X9, X7, S2210, S1400 and Truvativ AKA cranks. GXP® and Long spindle BB30 models (15mm spacer on drive side). Compatible with Boost148 as well. Size Options 28T 30T 32T 34T