GSM Calculator Bug
This looks like a typical calculator, but has a built-in voice-activated GSM bug audio listening device. The product is fitted with a rechargeable Li-Ion battery – the standby time is around 8 days.
You can use SMS controls to toggle the voice activation on and off. The GSM band modules are 900/1800/1900. To tune into the audio listening bug, simply dial the internal SIM card number and listen in. This cleverly designed unit is great for listening to conversations and on the outside it is inconspicuous, so can be left lying around.