Excellent for cross bikes or for any urban or touring bike where being able to brake from the top of your drop bars is desired. Works with your STI levers. Can also be installed alone as you might do on a track bike. Hinged clamp fits 24.0mm diameter. A nice touch is the slanted barrel adjuster. Light alloy construction. (31.8mm OS version below.) 24.0mm clamp levers sold as a pair or left only.