The Park Tool Hex Tool is made with strong steel and is long for proper leverage. This 10mm version is made for crank bolts which can be found on components from brands like Campagnolo and Ultra-Torque. The long end features a 10mm hex while the short end has a ball end hex. An ergonomic screwdriver grip makes it easy to use and gain leverage. The Park Tool Hex Tool is a great way to tighten bolts with confidence.