It protects you from the sun, wind, and other elements. 
• 82% polyester, 18% spandex
• 6.78 oz/yd² (230 g/m²) (weight may vary by 5%)
• Very soft four-way stretch fabric that stretches and recovers on the cross and lengthwise grains
• Fitted design
• UPF 50+
• Comfortable longer body and sleeves
• Flatseam and coverstitch