Timberland Women's Boots Black Leather Laces Flats Sensorflex Ankle size 9.5 In excellent condition T he SensorFlex™ comfort system is a three-layer outsole that delivers constant support, active cushioning and dynamic flex. The firm upper layer provides all day-comfort and stability, a softer EVA middle layer adapts to uneven surfaces, and the bottom outsole layer features a grooved sole that flexes with every step.