These work beautifully, absolutely as described. I had been using tiny styrofoam craft balls as stoppers for sock knitting, and these work so much better. One tiny flaw, is that the plugs had not been fully punched out in the manufacturing process and I had to force out each one from every hole in every piece. The bigger issue, the one that keeps this from being a 5-star review, is that they are foam, and being such, means they are very susceptible to static electricity. They stick to things and are hard to shake off, especially in the very dry winter months. I highly recommend them, but just be aware this may make you a little crazy.