Series 3400 Headsets are designed to provide crisp, clear communications and effective hearing protection in high noise environments. They are engineered to be compatible with David Clark Series 3100, 3400 and 3800 Intercom Systems and Series 3000 Mobile Radio Adapters. The Model H3492 is a single-ear, over-the-head style headset capable of affording comfort and communication clarity over long periods of time. It utilizes the M7-A electret, noise-cancelling microphone, delivering excellent speech intelligibility. A single noise-attenuating ear cup provides clear isolated reception of the connected parties by either intercom or radio. A microphone on/off switch is also included. Durable construction and quality components are found throughout the Series 3400 headsets. Comfort features such as the ear seal and headpad are specifically chosen for exceptional comfort in any temperature or environmental conditions. David Clark created the world's first noise attenuating communication headsets and continue to lead the world in delivering quality communication tools.