I bought one of these 5 years ago and it stopped working. But then I found the directions for resetting the frequency and that fixed the problem. So, I bought a second. Both are working great. I like that they are small and easy to take to class. I also like that I can put any kind of treat in them which you can't in the Manners Minder. That is especially important for my picky small dogs or when I need to dispense high quality treats for harder behaviors like independent weaves. The only problem is you have to replace the treat every time but that aspect is offset by the ability to use any kind of treat in them. I wipe out the slobber and crumbs after every training session and that has kept it pretty clean and working well.