This tool set includes 27 metric chrome combination wrenches of various sizes. Combination wrenches are drop forged from steel bar. These wrenches are available in fractional sizes from 1/4 in through 2-1/2 in and in metric sizes from 6 mm through 60 mm. These are general purpose wrenches designed for a wide variety of work. This wrench combines a 15 deg angled slotted opening at one end and a 15 deg offset 12 point box opening at the other end for improved gripping. The openings are of the same size. Use the slotted opening generally for quick run down. Use the box end for final tightening and/or to avoid obstructions. All 12 point box openings through 2 in fractional size are \"Lobular\" design which reduces the risk of fastener rounding, provides a better grip on worn fasteners and allows more torque to be applied to the fastener. Martin Wrench Set, Metric, 27 Piece, Forged Alloy Steel, Polished Chrome