I have been looking for 1/4 inch bolt extractor for professional use, these simply work. I extract a few rusted out bolts without a problem simply because all 16 pieces have a very small increment, there has to be one that fits if a 6mm-10mm bolt get rusted out. Built quality is top notch too,they are hardened steel alloy, there are not cheap metal that will shear off easily.
Rating: [5 of 5 Stars!]