Features
1. GPS SIRF-Star III chipset fast fixing the position even at a weak signal status.
2. Works worldwide! Support 3-frequency GSM 900/1800/1900 MHZ.
3. Receive phone calls and SMS and GPRS in three way communications.
4. Monitors can track the device without interfering him, LIVE! Real-Time tracking!
5. SOS button send out exact location for immediate rescue/action.
6. Independent SOS button which will send GPS information via SMS for 1 to 5 preset numbers.
7. System setting by SMS. FREELY!
8. Low battery notification before the battery runs out! Worrying free on why the locator wouldnt     respond for this kind of situation!
9. Speed limit alarm
10. Multi-user management on website. (GPRS mode)
11. It has data logging function and records up to 20400 way points.
12.The wrist GPS tracker can display the time and positions of the wearer
13.With A-GPS,the receiver can acquire satellites and provide accurate postition 
 data instantly on demand,even under poor signal conditions.

Specification
GSM/GPRS:
GSM/GPRS :module:Sincom300 Tri-Band GSM module (GSM900/1800/1900MHz)
GSM Antenna : Build-in
Protocol: Support TCP transmission
GPS:
GPS module :SRIF III 20 channels
Protocol :NMEA-0183 compliant protocol
GPS Antenna :Build-in active high sensitivity antenna
Accuracy : 1-5m
Update rate : 1 HZ
Start time Cold start: 42s Warm start: 35s Hot start : 1s
Electrical:
Operating Voltage: 3.4-4.5V
Charge voltage: 4.5~5V
Standby :15mA
Operating :80mA
Battery Li-ion: 1100mAh
Stand-by time: 36hours
other:
Product Size: 68mm*47mm*17mm
Weight :55g(including battery)
Box Size :17.5cm*12cm*8.5cm
Weight : 260g
Carton Size: 53cm*38cm*47cm(for 40pcs)
Weight: 12KG