EnerTwist 4 Piece Stripped Screw Extractor Set ◆A Must Have in Your Tool Box for Anyone Who Works with Screws and Bolts Ideal for removing of stripped, broken, stuck, rusted, snapped off, damaged screws. Nice saving you from drill out pain! ◆Long lasting: With durable high speed steel 4341#, heat-treated and twice tempered for extra hardness 63-65HRC, providing you long lasting lifetime and great performance removal of the screws! ◆Smart: Lightweight less than 0.8 ounce and small size for easy carry ◆Easy use: Simple to use, just two steps! To use these types of extractors you use the drill side of the bit and drill out the screw head to make a round, smooth crevice. Then flip the bit over and use the left handed thread, grabber, thingy and put your drill on counter-clockwise. Pressing down onto the screw firmly and using a slow speed (200 RPM is enough) on the drill you will find that this bit actually bites into the metal of the screw, trying to drill down into the metal further, and the extractor bit will easily remove the whole screw. Remind: if the screw body has been embedded for a long, long, time, the screw head will actually break off! ◆Specification: contains 4 pieces damaged screw remover kit, packed in storage case. Removal capacity of the extractors as below: 1# - Remove Diameter 3~5mm 2# - Remove Diameter 4~8mm 3# - Remove Diameter 5~10mm 4# -Remove Diameter 6~12mm ◆Warranty: All your broken screw extractor set EnerTwist will offer worry-free one-year warranty on material defects and workmanship for the normal life of the product. Customer service are always open, any issues kindly contact!