I love the way people jump to conclusions straight away thinking about putting 2 dogs in the same Earth at the same time don't you ever think to ask first? Wank wods!! I enquired if you can link 2 collars up to a box as when out on a walk the other day and one of the dogs happened to fall down a 16ft man hole. It's just as a safety precaution for the future incase something like this happens again on a normal walk. I got a pup to bring on and wanted to check if there's something out there like the bellman or another device you can link 2 collars too just to see their where abouts incase you lo