The Pasternack gain horn antennas, also called microwave horns or horn antennas, are passive broadband devices. These are tshaped like a pyramidal horn to direct a radio waves beam at a certain frequency. These are also used to calibrate devices that measure the gain of other antennas. The Pasternack horn antennas can be ordered with or without a waveguide. These would be with a coax adapter attached to it. These are known as connectorized horn antenna. The line of products includes waveguide sizes WR15, WR28, WR34, WR42, WR51, WR62, WR75, WR90, WR102, WR112, WR137, WR159, WR187, WR229, WR284 andWR430. The waveguide portion is made of aluminum.