This noise reduction mic is LOUD! The Astatic RD104E Road Devil Microphone features a high gain amplifier with electronic equalization to provide maximum talk power and intelligibility even under noisy conditions. The Road Devil is a VERY powerful microphone. Pleas use diligence when setting the gain control to avoid any unnecessary feedback. The Road Devil Amplifier and six wire cable make it compatible with all modern radio transceivers. The Road Devil requires a standard 9-volt battery.