Designed to be worn in dress shoes, these insoles have six springs in the heel that return some of the energy of the downward footfall back up to the body for a "push off" with every stride. Many foot and ankle ailments stem from the impact of the body's weight while walking, which is why the coils are positioned directly underneath the heel. The suspension coils are only 1/4" thick, making them undetectable until a step is taken. The springs will never wear down or lose their shock-absorbing capability. The insole has a honeycomb padding with valves that draw in and expel air during walking for constant circulation to keep the shoe dry. EVA padding in the forefoot cushions and supports the foot. Men's sizes S (4-6), M (7-8), L (9-10), or XL (11-13); Women's sizes S (5 1/2-7 1/2), M (8-9 1/2), L (10-11 1/2), XL (12-13 1/2)