The powerful inductive coil will creat strong signals to drive earpieces within 40-60cm distance. One pc 35db top sensitive microphone ensures your partner hear the whisper voices, even the GSM Pen is hidden under the clothes. GSM Pen has a builtin rechargeable 500mAh battery.Supports more than 3.5 hours talking time, or 8 hours Standby time. This item is in the category "Consumer Electronics\Portable Audio & Headphones\Headphones". The seller is "henglystar" and is located in this country: CN. This item can be shipped worldwide.