Manufacturer: Okamoto Color: Pink Materials: Acrylic, wool, others Size: 23-25cm (Japanese shoe size) Recommended for those who can't sleep due to cold feet! These socks for sleeping warm your toes and help you sleep comfortably. The double-layered heat-generating material warms the soles of your feet and promotes blood circulation. The unique design, which only opens the toe area, lowers your core body temperature and leads to a good night's sleep. The heat-generating material on the heel stimulates pressure points and leads to relaxation. These are sleep socks from the "Marude Kotatsu" (Like a Kotatsu) series, which warms your feet from the bottom up with patented technology. For those who can't sleep due to cold feet or are anxious about having to sleep, these socks have three sleep-inducing features that warm your feet to the tips, enveloping you in a warmth like a kotatsu. [For Cold Prevention While Sleeping] They firmly cover the soles of your feet, where blood vessels are concentrated, and warm them to the tips of your toes. The open-toe design allows you to use them comfortably while sleeping without your feet getting stuffy.