Dully Halters?

[Dianne(GodMommy2Max)]

Anyone know much on these this is new to me, I am asking a lot of questions but keep in mind i havent worked with my own horses in nearly 3 years so im just doing so brush up learning?
Heard Monty Roberts talking about a dully halter on a video but mmm im not sure what this is

[risingrainbow]

This halter is Monty Robert's trademarked thing. He swears there's not halter like it. I've used one. It's expense and is no more effective than a good rope type halter. I wouldn't waste my money when you can but a good rope halter for half the price.