With thin, structured support, Superfeet Black Synergizer Insoles create a perfect fit for all foot types in tight fitting or lightweight footwear. . Recommended footwear: Lightweight running, cleated, athletic, mountain biking, golf, and all types of casual and dress footwear. Ideal for all arch types. Maximize foot function while improving fit Superfeet help enhance your natural movement and propulsion without sacrificing comfort and support. High density foam Foundation provides durable biomechanical support resists moisture and helps reduce shock while offering advanced comfort. ESS Encapsulating Stabilizer System for optimal underfoot support, comfort, and stability creates a deep heel cup to cradle the heels fat pad for improved natural shock absorption. Top cover treated with Agion antimicrobial technology to provide long lasting protection against bacteria. Trim to fit. Men's U.S. shoe sizes: C 5.5 7 D 7.5 9 E 9.5 11 F 11.5 13 G 13.5 15. Women's U.S. shoe sizes: B 4.5 6 C 6.5 8 D 8.5 10 E 10.5 12.