With a springy midsole, energized cushioning and clever technologies to keep your natural line of motion without twisting, you can focus on achieving greater distances every time. The GEL-NIMBUS® 21 PLATINUM shoe features I.G.S® (Impact Guidance System) technology to enhance your natural gait. A GUIDANCE LINE™ sole helps to stop you twisting, while TRUSSTIC SYSTEM® technology - a moulded component under the midfoot - provides extra stability and increases stride efficiency. In the midsole, FLYTEFOAM® Propel technology puts a spring in your step; it's a lightweight foam with a high-energy return elastomer for great bounce and unrivalled toe-off. GEL® technology in the rear and forefoot is a silicone material strategically placed to offer excellent shock absorbency - crucial for long-distance road runners. For extra comfort, there's even plush cushioning in the SpEVA 45 lasting, which provides added stability too. The shoe has a Jacquard mesh upper to help air flow freely to the foot, while the AHAR® heel plug gives added durability. This AHAR® sole is a tough compound which helps reduce wear and tear. The external heel counter grips the heel for a comfortable fit, while there's further support from an EVA sockliner. Running in low light? We've added even more reflective detail to ensure visibility when the evening draws in - so you can run when you want.