Spy Bug can automatically call you when it hears talking or increased activity. Or you can call the device at your convenience.
Just send a text to the secret gsm spy bug listening device and it will call you back. Put the phone down when you have finished listening & it will call you again when there is more activity. You can hear this GSM spy device from anywhere; you just insert your GSM sim. When you call the mobile number, this device will auto answer. You can hear talking or whatever you are listening for when you call in to the sim card. Useful at home with the babysitter, teenager ect. No flashing lights or sounds when activated by your call

This two-way gsm spy bug listening device comes with two amazing functions:
(1) Make a call to the sim card spy bug and you can instantly listen in to conversations! The built-in microphone works up to a 7 meter radius, so set this bug up wherever you want!
(2) Allows the spy audio device to call you when it hears people talking! This feature makes it much more advanced than most other GSM audio bugs on the market today.

At a Glance...
"    Hidden Audio Spy Gadget
"    Auto Dialing option
"    Tri-Band GSM Audio Spy Device
Microphone Range: 5-7 meter radius
Power: Built In 200 mAh Rechargeable Li-ion Battery
Working Time: up to 5 hours
Standby Time:
Voice Control On: up to 3-5 days
Voice Control Off: up to 10-15 days
All estimates are based on a fully charged battery with ideal reception.
Dimensions: 4 x 3 x 1 (cm)