What's a sounder, sorry for asking lol, dogs 4now and works well below ground I lost two dogs last season so I have two pups on the go now for next season what I am trying to bring on , I have two false earths on some land which drag the tails of the foxes through to get them going down, some have block ends so pups have to learn to back up, and some have tight spots , it works well I think it does ,