The RIDGID 35580 1/4 in. to 1/2 in. Diameter Screw Extractors (Set of 5) effectively remove broken or damaged screws. The set includes screw extractor models 1, 2, 3, 4, and 5. The Model 1 extractor uses a 1/8 in. drill (sold separately) to extract 1/4 in. screws from a maximum depth of 1 in.; the Model 2 extractor uses a 3/16 in. drill (sold separately) to extract 5/16 in. screws from a maximum depth of 1 in.; the Model 3 extractor uses a 1/4 in. drill (sold separately) to extract 3/8 in. screws from a maximum depth of 1 in; the Model 4 extractor uses a 5/16 in. drill (sold separately) to extract 7/16 in. screws from a maximum depth of 1 in; and the Model 5 extractor uses a 11/32 in. drill (sold separately) to extract 1/2 - 9/16 in. screws from a maximum depth of 1 in.