Six lobed spiral bits are designed to remove rounded or stripped fasteners with internal drive heads, Four sizes of extractors fit Torx and Torx Plus sizes T-40 to T-55; internal hex sizes 1/4" to 1/2" and 6mm to 13mm, Choose the extractor that fits snugly in the fastener, turn counter-clockwise to remove fastener, It may be necessary in some applications to drive the extractor into the fastener with a hammer for maximum engagement, Made of heat-treated alloy steel for durability, SKU: ISN14642