Looking for best dog training shock collar, complimentary for chastity training. What are the most important features? I would assume that the receiver should not have power button. This one here: https://www.amazon.com/gp/product/B01N1T9MD2/ has a Continuous and Convulsive Shock, which seems like a good feature that I have not seen on other ones. What are the best ways to attach it? Looking forward your suggestions.