Chromag sequence dm boost chainringchromags sequence dm boost chainring uses officially licensed sram x sync technology for unmatched chain retention chromag are the only mtb company who has the official authorisation to make chainrings using x sync technology regardless of the kind of mtb bike you possess you can rest assured your chain will stay put enabling you to give the bike a little extra flair with timeless chromag styling featuresmaterial cnc machined 7075 t6 aluminiumofficial sra