E-Thirteen Helix R Direct Mount Offset 3mm 11\/12V Black Chainring

A new technology. Combine with the chain, derailleur and shifter of your choice without changing the quality of the chain retention. Build a dream bike with more freedom and creativity. The updated narrow M4 tooth profile improves reliability, reduces chain noise and decreases system wear.Details 3mm offset, for Boost frame (12x148mm). Direct-Mount Sram (3 screws). Material: Aluminum 7075-T6. Tooth : 28, 30, 32 and 34 teeth. Speeds: 10, 11 and 12 speed Shimano and Sram. Weight: 48 g in 28T, 50 g in 30T, 52 g in 32T and 54 g in 34T.