Having used them a few times I'm a bit disappointed in them and regret not having spent the extra money on genuine Vics bits. They're a bit sloppy and the quality just doesn't seem to be there. Often the sawdust gets stuck in the nozzles and they stick, then you have to remove them, take a pair of pliers and twist the ends to loosen them. So they work well enough for a person who probably only uses them a couple of times a year, but if you're a regular carpenter you won't like the quality here.