The Superfeet GREEN is their most popular insole, having been on the market for over 30 years. Designed primarily for footwear with a removable insole, it\'s recommended for those seeking maximum support and shock absorptionGiving maximum shock absorption, they are ideal for feet with medium to high arches.Recommended for use with any running, walking, hiking, alpine, industrial, and military footwear.Superfeet Insoles are designed to be trimmed to size, to give you a perfect custom fit if you need it. Use the size chart to give you the nearest approximate size of insole that you need. Go for a size that\'s a bit too large, rather than too small, you can then trim the insole down to the perfect size for your feet and footwear. (You can either trace around your footwear\'s existing removable insole, or around the footwear itself and then trim the insole down to size.)FOUNDATION Superfeet\'s XLPE (cross-linked polyethylene) foam, FOUNDATION, provides durable bio-mechanical support. This ultra-light, closed-cell foam resists moisture and helps reduce shock while offering advanced comfort. FOUNDATION\'s resilience and strength optimizes the performance of all the Superfeet Trim-to-Fit Premium Insoles.Agion Superfeet treat the top covers of all their Trim-to-Fit Premium Insoles with Agion antimicrobial technology. Agion\'s natural, silver-based antimicrobial is built right into the insoles, giving long-lasting protection against bacteria. Agion adds continuous cleanliness to Superfeet Premium Insoles, creating a clean, comfortable combination. Encapsulating Stabilizer System [ESS] Superfeet Green insoles feature a unique stabilizer cap for optimal underfoot support. When integrated with the shape and design of the foam full length, this combination creates a deep heel cup to cradle the heel\'s fat pad for improved natural shock absorption. This system provides comfort and necessary stability for different activities, footwear and foot types.