Bits are not guides to cut into a broken screw cap. I could never get them to drill a pilot hole to make the extractor work. (Maybe others = why two stars) The bits are right handed and the extractors are left handed as they should be but the tips need to be blunt to get started. It's disappointing that they don't work well, but I haven't found any extractors that work yet. And as stated in another review, = delivered in plastic.