The Under Armour Women's ColdGear Authentic Mock is a top choice for women's running base layer. It is made with a dual-layer fabric that provides a warm and comfortable fit. The ColdGear technology helps to keep you warm and dry by trapping heat and wicking away sweat. The mock neck design provides extra coverage and protection from the elements. This base layer top is perfect for cold weather running or any outdoor activities. It is highly rated and one of the most wished for items on Amazon.