Description:1. The stud extractor tool uses a 3/8 inch-drive, best used with an impact wrench and ratchet. Also compatible with flat wrenches, adjustable wrenches, sockets and crimping pliers.2. This pull tool is adjustable to fit earrings from 1/4 inch to 1/2 inch (6mm to 12mm) in diameter. Made of chrome vanadium steel with chrome molybdenum jaws and quickly remove broken and damaged threaded studs.3. This extraction tool is easy to operate and can help you get more time to rest, whether it is the exhaust manifold, fuel cap, broken screws, or broken, painted, rusty post mounting bolts are effectively removed, but the threaded surface may be slightly worn due to the high clamping force. Operating Guidelines: Place the extractor on the pin and rotate the lower flat hex nut counterclockwise to tighten the jaws. After the jaws hold the broken screw or pin firmly, continue to rotate the pin counterclockwise until it is removed. Then release and separate them clockwise. But the threaded surface may be slightly worn due to the high clamping force. Specifications:Color: Silver + BlackApplication Scope: 6-13mm Material: MetalPackage Included:1*Broken Screw ExtractorNote:1. Please allow 1-3cm differs due to manual measurement.2. Due to the different display and different light, the picture may not show the actual color of the item. Thank you for your understanding.3. The threaded surface may be slightly worn due to the high clamping force.