Specially selected using the duometric principle allowing total size coverage with minimum number of sockets sockets are manufactured from chrome molybdenum steel and have an manganese phosphate finish for added corrosion resistance sizes 22 24 27 30 32 33 34 36 38mm 78 1516 1 1 116 1 18 1 316 1 14 1 516 1 38 1 716 1 12 suitable for use with impact type air wrenches supplied in steel case