The Electro-Voice Model 619 is a dynamic omnidirectional microphone especially designed for a wide variety of communications and paging applications. It is adaptable for amateur, CB, aeronautical, and commercial base station installations, as well as for all paging applications. The wide- range smooth frequency response (70 - 10,000 Hz) makes the model 619 highly useful for group discussions such as panel shows on radio and TV, and public address applications like council and board meetings, and similar problem situations where multiple microphone installations require individual "on-off" operation. The model 619 features the exclusive Electro-Voice Acoustalloy® diaphragm. This nonmetallic diaphragm withstands high humidity, temperature extremes, and corrosive effects of salt air. The mechanical nesting principle of design by which the internal parts of the model 619 transducer are closely fitted one within another results in a mechanical structure that is nearly impervious to damage from mechanical shock.