For removing damaged nuts, Bolts & Fixings. As you turn the socket anti-clockwise the spiralled cutting blades grip and remove the nut or stud. Includes straight bar for removing the nut from the socket. 1/2" drive so will fit any 1/2" drive ratchets / bars / extensions etc. Sizes: 17mm, 19mm, 21mm, 23mm, 27mm. This high quality 5PC 1/2" DR Impact Twist Socket Set comes to you brand new with retail packaging. This is a perfect addition / replacement to any toolbox or workshop.