Low VSWR HELIAX Air Dielectric Coaxial Cable provides the pressure path to pressurizable microwave antenna feeds and are the recommended feeders for antennas with air dielectric feeds for 2.7 GHz and below. 7/8", 1-5/8" and 2-1/4" are the sizes typically used. Cables and connectors are available for standard U.S., Canadian, or CCIR frequency band. Other frequency bands are available on special order.