Unique ball-end design allows hex screws to be tightened or loosened at up to 25 deg.. Made of high-quality tool steel. Packaged in reusable plastic holders. 18-piece set includes .050', 1/6', 5/64', 3/32', 7/64', 1/8', 9/64', 5/32', 3/16', 7/32', 1/4', and 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm.