I have something similar, basically a stretchy tube you slide over the head after thoroughly damping it up. Cools from the evaporation of that water. Gets body warm, though, so you need to rotate it every now and again. DOES work, mostly, but I found that used while riding tends to evaporate it too fast. Seems to work better at a slower pace (not moving at bike speed) If it's really hot and I'm riding, I really want that air flow around the neck.