An assortment of standard hex keys from The Hillman Group. Also known as Allen keys, hex keys are L-shaped tools used to drive bolts and screws that have a hexagonal socket in the head. The contact surface of the screw or bolt is protected from external damage. Variants included in this assortment range from 3/32" to 5/16" in diameter. Full assortments of #4321 contain eight (8) refills comprised of Hillman item numbers #547, #548, #550, #551, #4320, and #4322 - #4324.