The Blue Spot 3/8" Impact Stud Extractor is manufactured from carbon steel for increased durability. Ideal for removing broken, stripped & rusted studs as well as threaded rods & broken bolt shanks. The impact stud extractor is fully adjustable to fit studs between 1/4" to 1/2" (6-12mm). Can also be used with a 3/8" ratchet, 24mm spanner or an impact driver on a low power setting.