supply with professional talored EMI/RFI honeycomb filters and Waveguides provide optimum EMI/RFI shielding with minimum pressure drop for the ventilating air. Shielded vent panel effectiveness is accomplished using waveguide honeycomb design principles. Their special design lets air flow into and out of an EMI/RFI shielded enclosure. This feature allows for the cooling of electronics as well as air circulation for manned military shelters as well as electronic boxes and cabinets. The circulating air can also be used to either heat or cool an area depending on the external environment.