Special internal thread design can easily remove damaged bolts, nuts and screws, even if they peel off, rust or freeze. 3/8 inch square driver, suitable for manual ratchet, impact wrench and pneumatic ratchet. The bolt and nut remover is made of metal and durable. Reverse spiral grooves are designed to engage to provide maximum clamping force. This set comes with 3/4 inch (19 mm), 11/16 inch, 17 mm, 5/8 inch (16 mm), 9/16 inch (14 mm), 13 mm, 1/2 inch, 12 mm, 7/16 inch (11 mm), 10 mm, 3/8 inch, 5/16 inch (8 mm), and 1/4 inch. Name:Broken nut extractor set Quantity:13pcs/set Colour:Black Material:Metal Package Contents: 1 * Broken nut extractor set 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.