Sixpack racing k ring narrow wide chainringthis narrow wide mtb chainring is specifically designed for use with 12 speed chainsets with a 104mm bolt circle diameter. It features a rock solid aluminium construction, which makes it more than capable of handling all the intensity that's associated with long days in the mountains. Sixpack racing has also put this model through a cnc machining process, which shaves off any unnecessary weight while also maintaining strength. This makes it a great choice of upgrade for riders who want a durable and dependable chainring that won't add any unnecessary grams to your ride.featuresbackplate material cnc machined 6061 t6 aluminiumfinish anodiseduse mtbbcd 104mmspeed 12 speedtooth profile narrow widetooth count multiple options available to selectbuy sixpack racing components from chain reaction cycles, the world's largest online bike store.