1. Built with squared handles, which makes it easy to tell 1/4 turn increments on the mixture settings. 1/4 turn is typically the increments you want when trying to tune a carburetor
2. Fits many brands of equipment, including STIHL, Husqvarna, Poulan, Weedeater, MTD, Troy-Bilt, Homelite, Ryobi and anything else that utilizes the adjustment screws