The US PRO 25pc Screw Extractor Drill and Guide Set is the ideal solution for removing broken screws and bolts without damaging the surrounding material. This comprehensive set provides the tools necessary for extracting fasteners ranging in size from 5mm to 16mm. Features : Extracts screws and bolts of various sizes. Suitable for thread sizes from 5mm to 16mm . Efficiently removes broken fasteners without breaking or jamming. Permits maximum torque expansion , ensuring easy removal of stubborn fasteners. Specifications : HSS drill bits : 1/8", 3/16", 1/4", 5/16", 11/32". Extractor pins : #1, #2, #3, #4, #5. Drilling guides : G1, G2, G3, G4, G5, G6, G7, G8, G9, G10. Extractor nuts : N1, N2, N3, N4, N5. Drill bits material : HSS 4341, hardness rating of HRC 60-62. Extractor material : 6150 CR-V, hardness rating of HRC 48-55. Brand : US PRO