I ordered the air pump. Thanks for the posting. Looks like a winner! The cooling vest s very interesting especially down here on swampy hot Treasure Coast. Temp and humidity can both be very close to each other so this type of cooling should work well. I have a vest with pockets for four ice packs that works too well. This circulating cold water that you can control seems like a better solution, other than the ice chest and pump assembly...but to stay comfortable and avoid heat stroke it’s a small inconvenience I would think... Gotta think about this one before ordering...cooler or backpack??? Hmmm....