Polarmax Single Layer are your standard dependable thermals. This women s crew neck thermal top fits like your favorite long sleeve t-shirt. Originally designed with the working professional in mind as a warm base layer this fabric features our staple Acclimate Dry fibers which work to transport moisture away from the skin as you go about your day. Single Layer thermals feature a flat seam construction for seam strength durability and longevity and a relaxed fit for everyday comfortable use.