General application: reduces pain and discomfort to the metatarsal (forefoot) region. Medical application: alleviates conditions of metatarsalgia, pain in the metatarsal region of the foot caused by conditions of "fallen metatarsal arch," "ball of foot" pain, Morton's neuroma (irritated nerve endings), and bursitis. How it works: the metatarsal lift provides a comfortable lift to the central (2nd, 3rd, and 4th) metatarsal heads. This will alleviate stress to the area and reduce strain to the metatarsal region. "Peel and stick" application allows you to find the correct location (as shown within packaging) on the insole of your shoe. They are designed to provide target relief for maximum effectiveness. Sizes: (measurement based on shoe size) Medium: men's (7-10), Women's (5-11) large: men's (10+ ), Women's (11+ ).