This is a super sensitive, voice activated transmitting microphone. It only transmits when it is triggered by audio and when no sound is present it shuts down, sending out a beep to inform that it is in a 'monitoring mode'. The vox switch can be adjusted to suit various environments. The unit's tuned transmission frequency is between 86 - 96 Mhz on the FM band. It is quite stable allowing for strategic positioning in a room for monitoring. It has a 160 cm wire antenna and will transmit up to 500 metres, requiring 1x 9v 'snap on' battery, lasting up to 350 hours of use.

This unit requires a receiver such as FM radio to pick up the signal. A radio with manual tuning (not a digital read-out) will give better reception as it allows more accurate tuning. Once the battery is connected, the unit is on and can be tuned into the radio for clear reception.