This set is designed for removing damaged, rusted or worn screws, bolts, studs and staples. Screw drill bits made of steel, high hardness, good polish, durable in use < p>Extractors made of high quality tool steel with left-hand spiral groove for increased gripping power. Easy to use: Just drill a hole in the center of the broken screw with a suitable drill first, then use a suitable extractor to remove the screw The kit consists of 5 extractors, 5 screw drill bits, well packed in a plastic case. Product Description Specifications: -Material: Steel -Drill Sizes: 3/32, 1/8, 3/16, 1/4, 5/16, 3/8 -Screw Extractor: 1 (diameter: 4.0 mm/0.15) for 4-6 mm/0.15-0.23 2 (diameter: 4.5 mm/0.17) for 6 -8 mm/0.23-0.31 3 (diameter: 6.5 mm/0.25) for 8-11 mm/0.31-0.43 4 (diameter: 7.5 mm/0.29) for 11-14 mm/0.43-0.55 5 (diameter: 11.0 mm/0.43) for 14-18 mm/0.55-0.70 < p> 6 (diameter: 15.0 mm/ 0.59) for 18-25 mm/0.70-0.98 -Box size: approx. 19 x 10 x 4.5 cm Packaging contents: 1 × box with 6 pieces