MBT Women's Belle Mid Boot Burnished Dark Brown MBT Index: High. Upper: Nappa Leather with Faux Shearing. Foot-bed: Leather Lined. Mid-Sole: SensorTechnology. Out-Sole: Non-Marking XS-Trek Vibram. MBT SensorTechnology in the heel complements the midfoot sensor by absorbing shock. The MBT innovative Pivot Strike area provides runners with the ideal foot striking platform to transition into propulsion while enhancing support and cushioning. Non-Marking XS-trek Vibram Outsole is anti-static, oil and slip resistant MBT Women's Belle Mid Boot Burnished Dark Brown