Contents: Screw Extractors; #1; 2.5-4mm(1/8"-3/16"), #2; 5-6mm(1/4"), #3; 7-8mm(5/16"-3/8"), #4; 10mm(7/16"), #5; 12-14mm(1/2"-9/16"), Step Drill Bits; 4.5, 5, 5.5, 7.5, 10mm. Special design of the extractors cut into the side of the hole allowing increased force and make removing heavily seized fittings easier.