The Aetrex Orthotic System is Built-In to every pair: Our insole features arch support that helps to stabilize your body, align your feet and relieve common foot pain (ie.plantar fasciitis, heel pain & arch pain) Our insole features UltraSKY™; cushioning to provide pressure relief & comfort Our insole is lined with microfiber treated with antimicrobial technology to help fight every day odors Details: Adjustability: Stretchy knit collar Upper Material: Shimmery stretchy knit fabric Midsole Material: Lightweight UltraSKY™; for comfort Outsole Material: Rubber pods for durability Removable Insole: Yes Heel Height: .8" Padded heel for extra cushioning Machine washable