I.G.S (IMPACT GUIDANCE SYSTEM) TECHNOLOGY: ASICS design philosophy that employs linked componentry to enhance the foot's natural gait from heel strike to toe-off. AHAR PLUS OUTSOLE: Strategically positioned in critical areas of the outsole, this exceptionally durable compound is 50% more durable than standard ASICS High Abrasion Rubber. SEAMLESS CONSTRUCTION: The use of seamless materials reduces the potential for irritation and friction caused by traditional stitches and seams. FLYTEFOAM PROPEL TECHNOLOGY: ASICS energetic foam formulation that provides supreme bounce thanks to a unique elastomer compound. SPEVAFOAM 45 LASTING: Employs 45 degree full length SpEVAFOAM 45 lasting material for a soft platform feel and improved comfort. Upgraded with the all-new FLYTEFOAM Propel midsole, the RoadHawk FF 2 model delivers a lightweight ride with continuous cushioning. Feel the bounceback with each stride—from soft landing to energized push-off. Its seamless upper surrounds your foot with adaptive support and exceptional breathability in a streamlined, stylish package that begs to hit the road. Weight: 9.35. Heel Height: 21mm. Forefoot Height: 11mm.