Worn only at night during sleep. My son outgrew this size. Great condition. From Incrediwear: For those looking to reduce swelling, relieve pain, and restore mobility in their ankle or foot, the Incrediwear Infrared Ankle Sleeve provides targeted support to reduce inflammation and accelerate the body’s natural healing process. These are the benefits our Ankle Sleeve has to offer: Versatile Support The Ankle Sleeve slips on your foot and covers the area from the bottom of your shin, down through the arch of the foot. Not only does it support the tissues and bones within your ankle joint, but it also provides healing power in the plantar and dorsal regions of your foot, and the achilles tendon in the back of your foot. An Alternative to Compression The Ankle Sleeve does not squeeze your body in an attempt to relieve pain. Instead, it uses semiconductor infused fabric to aid your body's natural healing process in your ankle/foot. Upon contact with the skin, the semiconductors release negative ions that vibrate your cells, increasing blood flow and blood speed. More blood to the area means more crucial oxygen and nutrients. Do not bleach, iron or dry clean. I called: Tips from Incrediwear to Optimize Performance - Cold/warm water and no fabric softener or detergents with essential oils. Incrediwear also told me not to apply any lotion or oil before using their product - as the lotion or oil can be a barrier between the skin and the fabric, reducing performance outcomes.