A 15mm Allen wrench isn't used too often when servicing bikes but if you're pulling off a freehub on a Shimano thru-axle rear hub, it's a must. Add Park Tool's 15mm Hex Wrench to your toolbox arsenal and have your bases covered. The L-shaped wrench provides plenty of leverage and features a process known as through-hardening to increase durability. Through-hardening involves rapid quenching of the hot steel alloy to increase hardness for the purpose of boosting its strength. A chamfered tip ensures a precise fit.