Manufactured from Chrome Molybdenum steel. Wall Drive? sockets selected on Duo Metric? principle. Suitable for use with impact type air wrenches. Supplied in robust carry-case. Size Coverage: 26, 27, 29, 30, 32, 35, 36, 38mm, 1-1/16?, 1-3/16?, 1-1/4?, 1-3/8?, 1-1/2?.