The Ingco HHK12091 Ball-End Allen Key Set is an essential tool for tightening and loosening hex bolts. The set includes 9 wrenches of varying sizes: 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, 5 mm, 6 mm, 8 mm, and 10 mm. These wrenches are made of high-quality materials for strength and durability. The ball-end allows for better access to bolts at awkward angles.