I have a remote controlled one. The level goes between 1 and 10. I bought it on Amazon and basically looked for one that was for small dogs and specifically with reviews where people stated they shocked themselves and it didn’t really hurt. I’ve only used it up to setting 4 but it’s an intense feeling and very enjoyable in my opinion. Here’s the link I think it looks super cute on too. It also has a vibration setting and a beep setting which is fun if you like the fear of not knowing which button will be pressed.