Material: Nylon + Spandex. Skin-friendly, breathable, stretchy, non-slip, lightweight, and quick-drying material keeps you comfortable. The versatile design allows it to be worn all night on the left or right foot, or worn while sitting during the day. M: 22.4" x 3.5" / 57 x 10 cm, recommended for women's shoe size under 8 / men's shoe size under 6.5. L: 24.4" x 4.3" / 62 x 12 cm, recommended for women's shoe size over 8.5 / men's shoe size over 7. The tension of the night sock is secured with a strong fastening strap and can be easily adjusted to create the perfect amount of stretch for each individual. It can stretch the plantar fascia more effectively, allow for deep stretching, and relax the foot muscles. The plantar fasciitis night sock provides a continuous, gentle stretch throughout the night and offers orthopedic support for foot drop, relieving pain and stiffness resulting from plantar fasciitis, Achilles tendonitis, heel spurs, foot drop, flat feet, and tight calf muscles. Unisex adult men women youth night sock for plantar fasciitis and Achilles tendonitis, adjustable sleep boot splint sock. Wear in bed for relief from plantar fasciitis, tight calves, and Achilles tendonitis. It can help reduce or eliminate the first few painful steps in the morning.