Everyone needs a mid-layer that can be worn comfortably on its own or under a jacket or vest, providing protection against cold winds during chilly runs. The Run Easy Warm Long Sleeve Mid Layer is designed specifically for athletic use and features helpful details such as a honeycomb-structured fleece interior, a high collar for chin protection, and thumbholes in the sleeve cuffs. By the way, this mid-layer is a favorite among our employees! It's a versatile, warm, and stylish mid-layer that gives you the necessary energy on your way to the next milestone.