"The Columbia Skien Valley Long-Sleeve Shirt pairs Omni-SHADE Broad Spectrum UPF 50 sun protection with Insect Shield treatment, so a single layer covers both the sun overhead and the bugs waiting in the brush. A sun protection collar extends that coverage up around the neck, while the 100% nylon build keeps the shirt light enough to wear through a full day outside. Snap closures at the front and cuffs make it easy to seal out drafts or roll sleeves up when the day warms. What Our Gearhead® Experts Are Saying:""I stay dry even when the trail turns into a climb because the Omni-WICK fabric pulls sweat away before it soaks through, and the vents keep air moving the whole way up."""