Features:

Voice active monitoring.
Built in adjustable sensitivity voice active microphone.
Built in High sensitivity monitoring amplifier microphone
Built in phone number filter function, other phone will not allowed to monitoring.
Can used SMS to set active or deactivate sound active mode.
Built in shock alert active function, will call and send SMS when detect shock alert.
Easy to operate, just install SIM card and SMS setting for all function modes
Built in rechargeable polymer LIION battery, with capacity up to 4200mA
USB charging ways, can be used while charging.
Built in charger circuit allowed using in charge mode.

Specification:

GSM band module: 900/1800/1900
Voice sensitive: -75db
Standby power consumption: 6mAh
Working power consumption:200mAh
Power: 3.7V 4200mA
Charger power: 5VDC at 500mA
size: 110x60x40mm
Filter mode: 4 sensitivity