DIFFERENT SIZES -- There are a total of 6 extractors in different sizes for diameter screws. The steel tool pullers have a left-handed spiral flute designed for extra gripping power. Aggressive left-handed (extractors) and right-handed (drill bits) spiral flute design for extra gripping power. Design Concept -- This screw extractor goes through a rigorous process, surface polishing, high hardness, high torque. This set is designed to remove damaged, rusted or stripped screws, bolts, fasteners, metal water valve and water tube, etc. High Quality -- Adopting high quality tool making tool. steel which could drill on most screws., Have a long service life. Few bits can also be used to drill holes on wood, metal, plastic, brick and wall etc. and machine screws as well as PH, flat, hex or painted on screws and applied to hold household, office, and so on. Easy to Use -- Drill a hole in the center of the broken screw from first with a suitable drill, then use a suitable extractor to remove the screws. Diameters of drill bits and recommended extraction diameters of broken screws are engraved on the case Good Notes -- You can use with a tap handle which hold the extractor firmly; for the large puller, you can use an adjustable wrench. You can use an adjustable wrench to hold the extractor firmly when removing the screw. Near power tools, wear protective goggles and clothing. Scope of delivery: Six pieces