I'm quick to report a bad product to others. This rating is a clear recommendation. I have just received my third package. My stay-at-home project involves drilling hundreds of pieces of sea glass. Other 1mm diamond drill bits I have tried have a failure rate of over ninety percent. These bits fail at less than ten percent. I use a dremel. I bought a new Dremel thinking maybe my old one was part of my previous failures. It wasn't a Dremel. For example, I can drill a hole through a thick piece in less than ten seconds. I'll probably get twenty pieces, two holes from each of those pieces.