A Siren that responds to the urge to surge. But with a full grain leather upper and rubber bumpers at toe and heel it is built for durability. Merrell Air Cushion midsole with women-specific Q-Form technology smoothes out strides while maintaining alignment. Vibram Siren sole features heavier lug pattern in high-friction areas and tread for vital traction under the arch.End Uses: Light hiking or biking on trails or urban terrain in dry conditions. Best worn with mid to light weight socks.Slip Lasted ConstructionFull Grain/Synthetic Leather and Breathable Mesh UpperBreathable Mesh Lining4.5mm Anatomical FootbedNylon 6.6 Injection Molded Arch ShankQ-Form Triple Density Compression Molded EVA FootframeAir Cushion Midsole5mm Sole Lug DepthVibram Siren Sole/TC5+ RubberWeight: 1 lb.