BlueSpot 2 Pce 8mm Magnetic Nut Driver The BlueSpot 2 Pce 8mm Magnetic Nut Driver is manufactured from heated treated and tempered steel alloy for increased strength and durability. The 1/4" drive is ideal for use with power drills and electric screwdrivers for the precise driving of nuts, bolts and hex head screws. Strong magnets hold fasteners securely for ease of use. To activate the manufacturers lifetime guarantee, you will need to register the product on the Bluespot website within 30 days of purchase.