Best Singlespeed cogs(sprockets) on the market. Thanks to the unique tooth shape, narrow-wide profile and perfect roundness these sprockets will outlast any other aluminium counterpart.Size (Weight):16T (23g)18T (24g)20T (29g)Material: CNCÊmachined 7075 Txxx Aluminum. Long-lasting construction. 7mm wide.Finish: AnodizedCompatibility:ÊFits to almost every hub on the market. Please note that some freehubs may be a bit out of tolerance, so the cog may fit tight in such case. This is absolutely normal.Chain compatibility:Ê1X, 6/7/8/9/10/11spd chains. To utilize narrow-wide feature please use 9/10/11spd chain. (Not compatible with halflink chains.)Each tooth is much wider and square like compared to a commonly used shape. Addition of narrow/wide profile, taken from our award winning Sram spiderless chainring, provides additional teeth strength and offers greater chain retention if a tensioner or chain gets loose while riding. This is the first cog on the market offering such a feature.Cog fits Shimano type freehub bodies and offers a 7mm thick base to prevent the damage of alloy freehub under heavy loads. The teeth are central to the base, so they can be flipped around to double the life of the cog. Always use a new chain with a new cog (very cheap chains may not fit properly)ÊThe lightest solution on the bicycle market Ð period.