Neilsen 11pc 3/8in.Dr Bolt Extractor Set Great for loosening damaged nuts and bolts. Unique Spiral Profile which digs itself into the head of the damaged nut and thereby grabbing it to loosen it securely. Nut Sizes : 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 19mm. Depth : 27mm. 3/8in. Drive.