This 21-piece socket set from US PRO Tools features 1" drive, 6-point metric sockets in sizes ranging from 30mm to 80mm. The set includes an 8" (200mm) extension bar, a 16" (400mm) extension bar, a 20" (500mm) sliding T-bar, and a 1" drive ratchet. All sockets are 6-point single hex and are hardened to HRC 42. The set is supplied in a metal storage box and is compatible with any 1" drive ratchets, bars, or extensions.