Work frequency: GSM 900/1800Mhz (attention: only works with GSM 900/1800Mhz card ,can not be worked with CDMA card,3G &4G)
      

Sound activated (it will call you back when there is a sound)
      

Auto answer: call the device ,you will hear clear voice around the device in 10s secretly.

Power input: AC100~250V 50/60Hz.
     

Power Output: DC 5V, 400-500Ma.
      

  Microphone range: 5-10 meters.
    

  24 hours non-stop power supply.
    

   Voice activate function on: Stand-by time 1-3 days.

  Voice activate function off :Stand-by time 3-7 days

Notes: only support GSM 900/1800Mhz SIM card(can not be worked with CDMA card ,3G &4G)

Pictures: