Really pleased with this product, I have an Xl Bully, he has taken to it really well and has responded well to wearing the prong, he likes to wear it. he now has a structured walk with rules. I now enjoy walking him. Which makes him a more of a tired and happy dog. The product is very good quality and even though it looks like a torture device i tried it on myslef first for clarity. I received it in no time at all. I would recommend for anyone who has tried every other method without success, like myself. I would insist on some training to use it but a competent, patient individual could learn enough from YouTube to make it work for you and your dog.