Powerstep's ultra stretch night sock combines ultra-soft material, a comfortable sleeve design and an adjustable dorsiflexion strap which gently pulls the toes to stretch the calf muscle and soft tissues of the foot and ankle. By providing a gentle and effective stretch and keeping the foot in a neutral position, the ultra stretch helps alleviate the heel pain associated with common overuse injuries such as plantar fasciitis and achilles tendonitis when taking those first morning steps. Available in two sizes, sized by calf measurement. Color: black.