Love this dog training collar! I have bought other bark collars before that you needed to replace batteries often, not this one. It's rechargeable so a few hours plugged in and it's ready.This dog training collar is also sleek and slim so it's not too bulky even on little dogs. My dog is a Chihuahua that used to bark at everyone walking by. Not anymore. Also love how all the settings are adjustable. We have it on beep and vibration and it's very effective. No need to use the shock function if your dog doesn't need it