Features:Manufactured from heat treated Chrome Molybdenum steel. Designed to remove broken studs and bolts. Reverse spiral design for maximum grip. Recommended drill bit size (for pilot hole) etched on each extractor, suitable for high torque applications. Supplied in storage case. Specifications:Contents: 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), 7/16″(11.5mm), 15/32″(12mm), 1/2″(13mm), 17/32″(14mm), 9/16″(14.5mm), 19/32″(15.5mm), 5/8″(16mm), 21/32″(17mm), 11/16″(18mm), 23/32″(18.5mm), 3/4″(19.5mm), 25/32″(20mm), 13/16″(21mm), 27/32″(22mm), 7/8(23mm).