The GSM Triband audio transmitter works from an unlimited distance and it is very light (just 20 grams) and very small (38x35x10 mm). It's a highly versatile and valuable product as it's easy to use and to program.
It can be programmed from a distance through simple instructions sent via sms. This GSM Triband has a extraordinary function: can be programmed up to 3 numbers to monitor the area or set in order to be called by the same audio transmitter when the sensor detects the presence of voices in the surrounding area.
With this device you can hear background noise from any distance by dialing the number of the SIM card inserted inside and it lets you know with a phone call (VOX Circuit) that dials your number when it hears a sound or voice, so that you can safely listen, when necessary, without anybody realizing.
It has a highly sensitive microphone and consumes only 20mA on standby and 200 mA at full stretch.