The Original one and only absoluteBLACK Premium Sram compatible Direct mount BOOST 1X Oval narrow wide chainrings are designed for GXP, DUB and Long BB30 spindle cranks. This chainring is dedicated for Boost bikes (3mm offset). They are 100-percent optimized for Eagle. It is the most Premium oval chainring on the market with scientifically proven performance gains. This oval chainring with 3mm offset converts any Sram crank into Boost specific setup. Boost and non-Boost Sram cranks are identical. All the offset is achieved by the chainring itself. Our regular OVAL chainrings for Sram cranks have 6mm offset whether this one has 3mm. It is ideal for 1x 9/10/11/12 system and Singlespeeds! Our oval (elliptical) chainring does not compromise the work of the clutch mechanism in rear derailleurs. It also does not require a chain tensioner when using in singlespeed applications. Riding out of saddle uphill will become more pleasant. These chainrings also help you to recover after knee injuries as pedaling becomes smoother and less exhausting. It is the most advanced oval chainring currently on the market. The most advanced, Patent Pending alternate wide and narrow teeth profile currently produced, guarantee minimum 12 months of excellent chain retention capabilities! We mean it. Always use a new chain with a new chainring.