Special Features92% Polyester/8% SpandexOuter Layer: Stretch Polyester-Spandex finished with Hyprotecht® by HEIQ®Mouth Covering: Merino Wool Blend Mouth Flap with Hyprotecht® by HEIQ®Merino Wool Blend Mouth FlapStretch FabricHyprotecht® by HEIQ®UPF (Ultraviolet Protection Factor) 50