Spiral cut teeth provide a positive grip to remove rounded or damaged bolts. Can also be used on screw heads and studs.

Will fit heads sized 9, 10, 11, 12, 13, 14, 15, 16, 17, 19, 21, 24 and 27mm

Sizes 9 to 19mm are all 3/8" drive

Sizes 21, 24, 27mm are all 1/2" drive

Can be driven with a ratchet or metric spanner