Ok I have to weight in on this. I have seen the worst and the best of the chain training collar (tip) it is only for use in training purposes. Some dogs are gentle enough to use the nylon,some are not. However I have different collars and harnesses(see harness questions earlier)It is so Merlin knows what we are going to be doing and what I expect of him. If a person knows how to use then its great. I had a neighbor when I moved here that had a chain training collar on her rottie and her sheparad I showed her somegrizzly photos i used in my classes it was a rot that got hung up as it tried to jump out of a truck. She puts them loose in the truck (which is another total lecture) the next day I found nylon solid collars on them. BaSim if you know how to use it properly go for it I say. Merlin is strong willed at his heeling when birds fly over so I have to use one on him any thing else he just ignores.