ASICS GEL-NIMBUS 14 Running Shoes (4E WIDTH) Biomorphic Fit - Biomorphic technology is incorporated into the upper where the areas of highest deformation are found. This ensures a better fit, improved comfort, less risk of injury and enhanced performance. Personal Heel Fit - A special foam heel construction that guarantees a perfect fit around the wearers heel. 3M Reflective - 3M Reflective- Improved footwear visibility when running in low level light. A-Symmetric Lacing - A new lacing system that acknowledges the a-symmetry of the foot, following an anatomical profile of the foot providing excellent fit. I.G.S - ASICS Impact Guidance System or I.G.S is a technical shoe design philosophy that allows the athletes foot to perform in a more natural manner. ASICS high-tech I.G.S shoes are constructed in a way that enhances natural gait.