Ultra-Cool AIR Long Sleeve Inner with Thumb Holes - 1 Piece This is a single inner layer for sun protection. I purchased a set of 2 in size M from Nissen online shopping, but I'm selling one as I won't be using it. I am also listing this on other flea market sites, so if you are considering a purchase, please do so quickly. It has been opened but is unused. There are some fold creases from storage. It can be worn under T-shirts, etc. The fabric is very thin and feels cool to the touch. It has thumb holes, so you can protect your fingertips from the sun. Outdoor events Outdoor festivals Tennis Outdoor sports Sun protection Sun protection innerwear Sun protection innerwear Sun protection arm cover Wear-only UV cut Ultra-Cool AIR Long Sleeve High Neck Inner (Contact Cooling, Sweat-Absorbing, Quick-Drying, UV Cut)