Ive got a few different ones from Columbia. I have to say theres one of them I prefer the most for hot summer days.I dont know the model name of it, but the fabric is 100% polyester instead of nylon. It is definitely thinner weight material than my 100% nylon shirts, and the fabric closely resembles the feel of the Under Armour.Im a warm-natured person, and unfortunately have a lot of skin cancer in the family, so Ive always lathered up in SPF1,000,000 and threw on a short sleeve shirt…until I made the switch two years ago.I always felt like lathering up in SPF5000 kept me from sweating efficiently, but now I feel cooler with no sunscreen but a long sleeve shirt.