Waterproof and Omni-Heat insulated the Bugaboot Plus provides a secure refuge for little toes throughout the winter months. Waterproof suede and PU coated leather upper. Omni-Heat insulation and lining for additional warmth. Injection molded waterproof thermal rubber outsole provides lightweight durable protection. Omni-Heat Thermal Reflective - This thermal reflective technology helps regulate your temperature by reflecting and retaining the warmth your body generates, while dissipating moisture and excess heat to keep you comfortable.