Arise Echo Cogs are CNC machined from either 7075-T6 Aluminium or SCM415 cromo. The alloy cog is perfect for riders chasing that super lightweight drivetrain, where as the cromo cog offer better resistance to chain wear. Both Cogs are designed to fit Shimano 'HyperGlide' cassette hubs and have a 5mm wide built-in spacer, giving a more solid interface with the cassette body. 16T and above feature cut-outs to save additional weight. Color: Hard Anodized SilverMaterial: 7075-T6 alloySize: 14t, 15t, 16t, 17t or 18tMeasurements: for 1/2" x 3/32" chains, for Shimano HyperGlide systemWeight: 11g (0.4oz)-14t13g (0.45oz)- 15t14g (0.5oz)- 16t16g (0.6oz)- 17t18g (0.65oz)- 18t Features: • CNC Machined •Cog Width: 1/2” x 3/32”•Shimano HyperGlide fitment•CNC cut-outs to reduce weight on 16t and up