small GSM Box and wireless earpiece - It's all you need.

Features of GSM Box

    Two way covert communication via mobile phone networks
    Optimized inductive coil creates strong power for earpiece
    Built-in top sensitive 38dB microphone to pick up whisper voice

 Working Principles of GSM Box

    Build-in quad band GSM module that works in 850/900/1800/1900MHz mobile phone networks.
    Once insert a GSM SIM card and turn on the power, it will automatically pick-up calls from any mobile phone or telephone. The powerful inductive coil will creat strong signals to drive earpieces within 60cm distance.
    One pc 35db top sensitive microphone ensures your partner hear the whisper voices, even the GSM Box is hidden under the clothes.
    The Reset button allows you to cut off audio output signals to avoid earpiece detectors.
    GSM Box has a built-in rechargeable 950mAh battery.  It supports 6 hours talking time.  Full recharge takes 4 hours.

What in the package:

    1 GSM Box (including charger and cable)
    1 Wireless earpiece
    1 Battery for the earpiece (You can buy more batteries from here: http://simenibiz.com/earpiece/sony-337-battery)

Box size: 53*37*15mm Weight: 45g