Bolt grip for removing rounded rusty or painted bolts. Unique reverse spiral flute design securely grips & removes stubborn nuts & bolts. Can be used with a hand ratchet 3 / 8in square drive & has hexagon flats for use with a spanner or adjustable wrench. Universal lobular design for all types of fasteners. 5 piece set 3 / 8in 7 / 16in