Radio Modem (Transmitter or Receiver) bi-directional radio transmission point-to-multipoint RS485, RS232 and TTL. Built-in omnidirectional antenna. 10 selectable channels. Outdoor housing, Protection class IP65. Transmission distance = 6 000 m. Free field of view. 12Vdc power supply. Mounting on 50 mm mast. Mounting accessories supplied. (minimum 2 modems per link).