I just purchased this for our MH as our dump connection is literally inches from the ground with the hoses attached. It's been a real pain trying to dump at times as I found myself walking the sewage ...
Clamps on the extension are not necessary, as others have already said. I use mine occasionally, and it works well when I need to move waste uphill. The only negative for me is that dumping takes a lot longer than with the standard slinky hose. If I don't need to pump the water, there really is no benefit. It also uses a fair amount of water when operating.