ExOfficio Men's Size Chart Two of ExOfficio's premium technologies merge to keep you cool, odor-free, and protected from bugs wherever you venture. Xylitol-infused fabric provides active cooling when in contact with moisture, and mesh side panels keep the air flowing. UPF 50 fabric provides superior sun protection, with extra neck coverage from the stand-up collar and thumb slots to protect your hands. A hidden security zip pocket stows your valuables for worry-free adventures. BugsAway(R) apparel is treated with Insect Shield(R), giving you invisible, odorless protection just by putting on your clothes. The treatment binds permethrin to fabric fibers for the life of the garment, so it stays in your clothes-not on your skin-and lasts through 70 washes. It's effective against ants, flies, chiggers, midges, and ticks, as well as mosquitoes, which can transmit insect-borne diseases such as Zika, Chikungunya, Dengue, and West Nile viruses. Silvadur(TM) delivers odor resistance for the lifetime of the garment, for less washing and more wearing, so you can pack lighter for your adventure. Features: - Front zips to chin for improved sun protection - Underarm mesh ventilation - UPF 50 sun protection - One hidden security zip pocket on right side that fits passport - Thumb loops - BugsAway(R) odorless insect repellent - Center back length: 29in - Natural fit - 92% Polyester 8% Elastane