FreshIQ3; advanced odor protection technology attacks the odor-causing bacteria in your clothing that causes your underwear and socks to smell - so now you can feel fresh all day. Made with our premium 100% combed cotton is the ultimate in comfort. Tag-free for itch-free comfort. Lay Flat Collar is designed to keep its shape. Length of Tall Crewneck is 2 inches longer than the XL sizes.(For more specific sizing refer to the sizing and size charts.)