These work but need to be tested first. I decided to test each bit on a piece of wood. What I noticed is that not all sleeves slide smoothly. The next step was to unscrew each of them to see why. First, not all of them unscrewed easily, not because they were too tight, but because there was something in the grooves. I found the feathers to look old or too long. On the 7/64" bit the wire washer was loose which prevented it from sliding properly. I was able to fix it but the ring can easily be lost if you are not careful. It got stuck in the sleeve. It took some WD40 and a hammer to get it out and in this case the spring was over the barrel so it was stuck in the case.After cleaning the bits worked better.For occasional home use they will be fine but I see the springs need replacing Maybe I got a bad batch or this product didn't work or it's just bad quality. They were made in China. I wouldn't buy them if I had to use them all the time.