STIHL Company have manufactured an excellent professional tuning screwdriver and here is is

The length is  150mm or 6 inches and the blade length is 100mm or 4 inches. This really is a "must have" tool and a big improvement on the shorter ones. For years I have been a fan of the Blue Husqvarna Tuning Screwdrivers however now we have something equally as good, if not better, from STIHL in STIHL orange, which is totally Awesome!

You can do no better than Genuine STIHL Tools.