2. Spiral flutes are designed to embed themselves deeper into the metal as you turn the tool, so as the fastener resistance increases, the extractor's grip increases. 

3. Made of durable hardened steel and tempered twice for extra hardness, promising you a long lasting screw extractor tool of rugged material and outstanding performance.

4. A few seconds,2 simple steps get jobs done! Use a suitable size remover to drill a deep hole in the screw head and then reverse the screwdriver counterclockwise into the damaged screw until it is released.

Extractor Size: #1(2.5-4mm), #2(4-6mm), #3(6-8mm), #4(8-10mm), #5(10-16mm), #6(16-22mm), #7(22-27mm), #8(27-36mm).