Lululemon Lightweight Trail Running T-Shirt Cyan Blue Designed to be worn with a vest on trail runs, this tee has strategically placed seams and ventilation to help you conquer mountains of miles. lightweight, uv-protective fabric Lightweight UV protective Smooth Four-way stretch Sweat-wicking Quick-drying Mesh fabric panels for ventilation UPF 40+ provides very good UV protection to only covered areas. This item’s protection may be reduced with use, or if it gets stretched or wet. Sun exposure causes skin damage features Strategic seam placement on the shoulder reduces chafe from a running vest