KO-H-1A Field Telephone is extremely rugged, light weight, dust proof, waterproof, anti-vibration, battery operaed instrument which is suitable for connection to manual or automatic two-wire field telephone system. It's suitable for wire communication. The communication distance is within 21km. This product has the advantages of reliable and stable performance, clear voice, wateproof, anti-shock and good electro-magnetic compatibility. It's a neatly styled, lightweightm battery operated instrument which is suitable for connection to manual or automatic 2-wire telephone system. This highly flexible field telephone is extremebly rugged and provides excellent battery life from easily replacable standard D size cells. The body of KO-TXA-1A Field Telephone is waterproof and extremely rugged. The body contains the electronic circuits of the telephone, and the 3 D Alkaline batteries are housed in a separately-seated compartment underneath