I have a 11 month old Staffy x bull Arab who is very stubborn but very smart. I have tried everything to get him to stop nipping our feet and hands digging up garden and even taking socks of line. we are at our wits end then I found the dog line and I thought what do I have to lose. I decided ok I’ll give it ago. I’ve been on the 2-week rental Big Dog Training Collar and now on the last week we have decided to keep it as it has worked he is a lot better we still have a few more thing to deal with but I have to say it truly is a life saver. I would and will recommend it to everyone with stubborn dogs. The best thing about the dog line is that you can try it and if it doesn’t work for your dog you can return it. The staff at the dog line are fantastic very friendly and helpful. Big thank you to all.