BOB'S FAVORITE TECH SHIRT - I prefer 100% synthetic fabric when fishing warm climates. Body moisture is quickly wicked away from the skin, and the shirt dries fast preventing that "sticky" feeling, and allowing for complete freedom of movement at all times. I designed this shirt with this in mind, as well as the basic performance, convenience and comfort features that we all enjoy. The fabric is 100% polyester nylon with UPF 40+ sun protection. It's lightweight, easy care, quick drying and wrinkle resistant. A fully ventilated back and a mesh interior yolk ensure excellent breathability, moisture transfer, and fantastic comfort. I squared off the bottom of the shirt so that it can be worn in or out (GREAT!). The two large front chest pockets have VERTICAL ZIPPER CLOSURES with easy-grab zipper pull-tabs. YOU'RE GONNA LOVE THIS POCKET DESIGN. They are fast to get in/out of, and offer superior security over any other design I've used. Two accessory loops for hanging a nipper or sunglasses. Roll-up sleeve tabs convert shirt to half-sleeves if you like. Hidden button-down collar prevents wind flap. THE BEST. No annoying logos on this shirt. SIZES: M(chest 38"-40"), L(42-44), XL(46-48), XXL(50-52), XXXL(54-56) in COLORS: (1)Caribbean-Green, (2)Caribbean- Blue, (3)Sunrise, (4)Forest, (5)Shadow, (6)Khaki, (7)Sage