The Steiner Active base layer set is designed to keep you warm. Made from a combination of viscose rayon and spandex, the Soft-Tec active range is comfortable to wear owing to its soft jersey construction and integrated stretch system. The fabric feels soft to touch and is an ideal first layer to wear against the skin. The viscose rayon creates a proven thermal layer that is technically advanced and sustainable. Tried and tested this thermal layer will keep you warm on your outdoor adventures.Manbi Mens Steiner Soft-Tec ACT Set Features: Lightweight and warm thermal layer Merino like soft jersey compact spun yarn Comfort fit with multi stretch Soft internal non irritation seams 95% Viscose Rayon 5% Spandex