The Impacto Sorbo-Air insole is made of sorbothane, is packaged 16 pair per case and comes in blue/yellow. Proper sizing is important when buying this product. The size for this product is 4 to 5. These types of parts are designed for specific applications which feature ways of safeguarding & shielding itself and/or the user. This product is designed and manufactured such that it offers the following protection: Shock Absorption.