The Teng TBNSI5 Impact Nut Setters Set contains a selection of nut setters for use with impact power tools. Made from S2 steel material with HRC50-60 hardness. The design creates even higher torsion for easier use. A recessed magnet holds the fastening (ferrous materials only). Supplied in a handy storage case. Sizes 1/4in, 7mm, 8mm, 10mm, 13mm