The Skil Tri Driver fits both inch and metric fasteners, and is adjusted by rotating the ring.
The Skil SKL013488 Tri Driver 14-in-1 Ratcheting Wrench is a great addition to any toolbox! With 3 ratcheting steel cams that automatically grip fasteners, it makes it easy to grip on to nuts & bolts. There are 14 different measurements to get various jobs done. Product Details: 3 Racheting Steel Cams Automatically Grip Fasteners, fits 7 SAE and 7 Metric Fasteners 9/16 in - 15/16 in 14 mm - 24 mm.