Smallest GSM Two-way Audio Voice Detect SIM Card Spy Ear Bug.
Specifications:

100% Brand New and high quality
Work frequency: 850Mhz/900Mhz/1800Mhz/1900Mhz (Quad-band)
GSM voice/Audio monitor Bug, not suitable for either CDMA or 3G network
Excellent stand by and working time, comparing to other similar products
Prominent sound quality makes spying more reliable
Voice activation, you can call back your phone automatically when the sound arround it up to 45DB
You can send message command or cancel voice activation function by easy SMS "1111" or "0000" only
Ultra tiny dimension: 4cm*3cm*1.2cm
Power Supply: 24 hours Non-stop
Microphone Range (Meter): 5~7(Radius), 4 levels
Working Temp: -40~50'C
Responding Frequency: 1.2K~800Khz
Standby time: 2-3 days (If Acoustic Alarm function Off, standby time: 10-12 days)
Working Time: 5hours
Compatible with All GSM SIM card

Instruction:

Open the back cover. Sim card into the deck will automatically boot.boot light is 3 seconds. after the lights go off you can dial the sim card number.
Installation: Please confirm the GSM network signal strength.So as not to affect the results cause can not be used
Number of settings: call the sim card numer with mobilephone or telephone,hang up then setting success
Voice feature: Send “1111” message to the sim card number then voice cotrolling is open;Send “0000” message to the sim card number then voice controlling is closed.
The flash of red light indicates the SIM card is correctly inserted. SIM will completed initialization and maintain in stand-by status and the light will be off and it is ready to go
Dial the SIM card number, you could hear the sound around the SIM card
Charging method: When the device is fully charged up, only Red LED lights ON. the Green LED light will OFF