The ActiveIce Spectrum Sun T-Shirt is built with thermoregulating ActiveIce(TM) technology, UPF 50+, and bluesignA(R) approved materials, perfect for keeping body temperature in check while hiking, backpacking, climbing, or setting up camp. bluesign-Approved Materials with Thermoregulating ActiveIce for Sunny Days The ActiveIce Spectrum Sun Long Sleeve Tee is built with thermoregulating ActiveIce(TM) technology and bluesignA(R) approved materials, perfect for keeping body temperature in check while hiking, backpacking, climbing, or setting up camp. This tee is built with an ultra-comfortable, breathable, and quick-drying polyester blend treated with our proprietary ActiveIce(TM) technology. ActiveIce(TM) reacts to your body&';s rising temperature by cooling down your core, keeping you in the sweet spot longer while pushing the tempo or working hard. The chafe-free design, built-in stretch, and UPF 50+ are welcome essentials for long days spent under the sun, delivering comfort and maximum range of motion on reachy boulder problems or tight slot canyon squeezes. Purpose-built for staying cool while spending long days in the mountains under the sun, the ActiveIce Spectrum Sun T-Shirt is a warm-weather staple for every outdoor enthusiast. Fabric Performance: Breathable Movement Mirroring Stretch Quick Drying Recycled Polyester Thermo-Regulating Cooling ActiveIce(TM) Treatment UPF 50+ Wicking Design Features: 2025 Updated Logo Chafe-Free Design with Dynamic Reach Interior Center Back Locker Loop Side Slits at Hem for Better Movement Fabric bluesignA(R) approved 94% Polyester, 6% Spandex Center Back Length 71.1 cm / 28.0 in Weight 4.94 oz/ 140 g