The 4063 Miniature Omnidirectional Microphone, Loud SPL and Low voltage is designed for use with transmitters giving only 3V bias voltage. Some transmitters provides only 3V instead of the more common 5V. In this case, the 4063 is the right choice for such transmitters. With the correct power source, the microphone will be able to handle sound pressure levels up to 138 dB before clipping occurs.