An assortment of metric square keys from The Hillman Group. Square keys are small bars of any length with similar height & width. They are inserted between a shaft and a hub to prevent relative rotation. Variants included in this assortment range from M4 to M8 in diameter and from 25mm to 50mm in length. Full assortments of #45976 contain twelve (12) refills comprised of Hillman item numbers #403543 - #403554.