Sizes: Women 9-11 Men 6-9.5 The Hydas Fresh Air Shoe pad delivers fresh air into your shoe by way of an auto-inflated airbag that ventilates even the most unreachable corners of your shoe. The airbag a one-way valve an air-circulating tube and a ventilating hole can all be found around the heel. Literally eliminating odor causing moisture and keeping your feet dry comfortable and healthy step by step.