These are good value parts so you get what you pay for. The set screw holding the bearing down to the smallest bit fell out and the bit ripped a large chunk out of my jig and the piece I was working on. Two medium sized cutters worked flawlessly. And the largest, the 1 1/2" cutter, is too big for the 1/4" shank. Too much tool chatter with this attachment, I didn't even try to cut with it. I was afraid the bit would fall out on its own just by turning on the router. Cheap bits for price and quality. You're fine as long as you make sure the ring holding the bearing is secure.