Simple, time saving, no more trouble for your project Designed to remove damaged bolts, screws and nuts. The spiral socket design allows safe attachment to the rounded fastener to be pulled out. It can be used with impact or pneumatic ratchet circuit breaker rod and reversible ratchet. Just place the socket on the damaged or round nut and bolt, and then turn it with the impact . Especially the hardened socket with anti-corrosion function. Non break stud round bolt. As more torque is applied, the grip on the fastener becomes tighter. Convenient storage. Maximum impact bolt remover/extractor: This kit is the perfect tool for removing stripped, rounded, painted and rusted bolts and nuts. Applicable hexagon size: 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm Outer hexagon size: 16mm, 16mm, 19mm, 19mm, 19mm, 22mm, 22mm, 25mm, 25mm, 27mm Colour:As Shown Material:Metal type:Lower Models Package Contents: 1 nut tools Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.