Features of the Marmot Women's Crystal Short Sleeve Top Sun protection with an ultraviolet protection factor (UPF) of 50 Lightweight, breathable, quick-drying, Performance-knit fabric Flatlock seam construction allows chafefree comfort Mesh panels for ventilation Raglan sleeve for comfort and increased range of motion Classic crew neckline Fabric Details 100% Polyester Knit 88% Polyester, 12% Elastane Single Jersey Mesh