ASICS Lady GT-2160 Running Shoes Personal Heel Fit - A special foam heel construction that guarantees a perfect fit around the wearer. 3M Reflective - 3M Reflective- Improved footwear visibility when running in low level light. *UPDATED* I.G.S - ASICS Impact Guidance System or I.G.S is a technical shoe design philosophy that allows the athlete's foot to perform in a more natural manner. ASICS high-tech I.G.S shoes are constructed in a way that enhances natural gait cycle. Solyte Midsole - Proprietary cushioning material that provides an exceptionally lightweight midsole with excellent bounce-back and durability. *UPDATED* DuoMax - A proprietary ASICS system that consists of two different density midsole materials and designed to provide guidance and control to prevent overpronation.