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.