Infra red therapy poll guards

[MoonlitArcher]

I have just stumbled across these online. My horse is very tight in his poll and I can often feel a bit of a crunching just behind his ears when ever he turns his head. He does have a regular osteopath see him and is on the waiting list for the horse back vet, but I was just wondering if any one has used these therapy poll guards, if so which one would you recommend and what exactly are they designed to do?

I had no idea they existed until 5 mins ago!
Thanks