10-Piece Set for a wide range of common applications across most common vehicles. These Hex head multi-spine extractors can allow the removal of broken studs, bolts, pipes, set screws, grease fittings, etc. Chrome Molybdenum steel. Reverse spiral design for maximum grip. Can be used with Sockets and Spanner wrenches. Recommended drill bit size (for pilot hole) lasered on each extractor. Suitable for high torque applications. Sizes: 1/8''(3.2mm), 5/32''(4mm), 3/16''(4.8mm), 7/32''(5.5mm), 1/4''(6.3mm), 9/32''(7mm), 5/16''(8mm), 11/32''(8.7mm), 3/8''(9.5mm), 13/32''(10.3mm).