This collar is working great for our monster Pomeranian puppy. I did a lot of searching to find a shock collar that would be okay for a small dog. This seems to be working great and there is plenty of room to make the collar larger if needed. Do not want to harm my puppy but do want him to behave. Shock does not seem to necessary hurt him but has made him behave much better as far as jumping on people and not running away when called. Would definitely recommend for behavioral issues.