Heat treated Chrome Molybdenum steel screw Extractors and fully ground step Drill bits. Ideal for removing right hand thread broken/seized screws and bolts. Step drills produce a conical hole which when used with the corresponding extractor provide increased grip to easily remove damaged fitting. Special Design of the extractors cut into the side of the hole allowing increased force and make removing heavily seized fittings easier. Supplied in storage case., Weight: 1.01192178258 pounds, Manufacturer: Sealey