This is the latest model of GSM box with electronic Spy earpiece. It's a complete set for talking secretly with anyone. The transmission distance is 25 to 30 CM from earpiece and MIC is very sensitive and can catch even very whispering sounds from long distance. 

Features 
distance between earpiece and Device is 25 to 30 CM maximum
Auto call receiving function 
1.5 to 2 Hrs battery backup 
Nano SIM support
100% clear sound

Box contains - 
1 GSM box
1 earpiece 
2 earpiece cell 
1 charging cable + Charger
 
Cautions - 
Don't use this earpice for longer time. 8 to 9 hrs is maximum use time since it's electromagnetic ways might harm if exposed for longer durations. 
Never sleep with earpiece in your ear
Do not insert forcefully. Don't push the earpiece as they might harm your ear canal/drum. 
The buyer shall not use the product for any illegal purposes and shouldn't permit anyone to use the product in any kind of unlawful activities. We promote our products for betterment for our lives not to go against law, or humanity.