These rivets do not require a machine to put them on. A hammer or pliers will work great. There are two pieces to each rivet you smash together. They are a very strong holding rivet perfect for fastening name plates. They come in 2 different sizes, 3/8 and 5/16. The 3/8 works well for Day-Glo collars, whereas the 5/16 is more for thick nylon or leather collars. They come in packets of 24.