Been wearing them for about six months.
So, I like to review the product as the guy made made them. At first I wasn't expecting the cooling effect at all. I just stood inside and pretending I was a used car inflatable dude, and my arms felt a lot cooler.
They're also a great base layer for my arm when it was cold. They feel a little tight getting them on and off because of the no-slip silcon cuffs, but once they're one, they're awesome.
Sometimes I be makin' good shit.