Mens Large 10-12 * Womens 11-13* Has A Semi-rigid Strap That Pulls The Toes Upward And The Foot Into A Slight Dorsiflexion Position * This Gently Stretches The Plantar Fascia So It May Heal * The Combination Of The Thermal Properties That Help Reduce Inflamation And The Stretching Of The Plantar Fascia While Sleeping May Aid In The Treatment Of Plantar Fasciitis * Non-slip Safety Soletm Rubber Grip Bottom Helps Prevent Slipping *