Jingrui series GPS/GSM alarms are design of metal shell all-in-one,possess power and stable functions ,install easy ,and compatible with all cars with 12 V voltage (including the car within alarm system original),at the prestent,this series provide five edition to different private car users to choose. This series adopt germany seimens factory-grade module GSMTC351 as network data changing communication/double frequency(900-1800MHz),GPS position receive adopt SIRF the three generation chip group,all product set 700mA back-up power ,working voltage scope :8.5v-15v: working quiescent currentú+80mA Alarm method :user phone,user phone sms,center sms alarm ,sound/light/mute alarm Alarm content:car operation ,open door,brake ,vibrate ,battery power-off,ask for help,slop over/electronical fence,speed alarm ect.,user inquiry car by SMS or network manage system.