The new Sidas 3 Feet Marino Mid Arch insole is designed to support a foot with a Mid arch to deliver more warmth, control and responsiveness to your skis. The new Marino Wool Cover adds a totally new element of warmth by adding extra insulation and odor protection. Skiers with medium or average arch heights require support to fill in the gap inside your boots underneath your foot. Adding an aftermarket insole is the single easiest way for you to improve the warmth, comfort and performance of your ski boots.