Developed and patented by Sievi, the SieviAir® sole solution takes care of your feet and improves footwear comfort. The SieviAir® system dissipates the perspiration from the shoe through special ducts in the side of the sole. Under the perforated insole there is a filter, which is connected to exhalation channels. With every step you take the filter is compressed, resuming its original shape when the foot is lifted. This movement produces a pumping action, improving the ventilation of the shoe. SieviAir® really allows your feet to breathe!