Description of Keen Bellingham Quarter Ultralight Socks - Women's 'Ultralite' weight, not 'lite' on features. Features: Material: Natural Merino wool & nylon/lycra An extremely lightweight casual style anatomically designed to fit her right and left foot Cushioning in key areas - heel and toe Anatomical Flex Fit system reduces bunching of material underneath feet Y heel pockets for better fit Lycra top to bottom for fit and comfort Ravel free double welt top to keep socks up Reinforced toe and heel for extra durability