SPECIAL socket wrench set, 7-piece with the key sizes SW 8- SW 10- SW 11- SW 13- SW 15 -SW 17 mm. Contents: 1 each hexagon socket wrench insert with 3/8' square drive and drive T-handle made of chrome-vanadium steel, specially hardened, high-gloss polished and hard chrome-plated. The special feature: With the help of the special key shape, even damaged (rounded) external hexagon screws can be loosened.