ASICS Women's Gel-Evate 3 Running Shoe 100% Textile and Synthetic Imported Rubber sole Shaft measures approximately 2.41" from arch Impact Guidance System (I.G.S): ASICS design philosophy that employs linked componentry to enhance the foot's natural gait from heel strike to toe-off. Fluid ride: fluid ride provides the ultimate combination of bounce back and cushioning properties with reduced weight and exceptional durability. Rear foot and Forefoot GEL Cushioning Systems: Attenuates shock during impact and toe-off phases, and allows movement in multiple planes as the foot transitions through the gait cycle. Guidance Line: Vertical flex groove decouples the tooling along the line of progression for enhanced gait efficiency. Guidance Truss tic System: This Truss tic System integrates Guidance Line construction for enhanced gait efficiency while providing midfoot structural integrity.