This is more than an alarm its a full management system

-Siren to make the noise
-It calls you when activated
-You can call it
-You can switch on and off a device in the car
-You can listen in for voices
-You can talk into the car
-If you forget to put your alarm on all you need to do is give it a call and switch it on
-If someone manages to steal it you can immobilise it buy cutting of the fuel or ignition
-You can track it using one of the services below

Everything is included in this system

-Central locking adaptor
-Engine start, start you engine from the house so its warm before you get in(cant be driven away)
-Battery back up
-Dial keypad for making hands free calls
-All the features are done using your mobile or regular telephone, simply give you alarm a call and follow the voice prompt, it also come with a regular transimiter for arming and disarming the system

Please note you do not need to plug your mobile into this alarm or you dont have to buy a mobile to plug into it ,, its all built into the main unit,, you put a SIM card into the GSM alarm main brain just like a mobile

NOTE:
THIS GSM CAR ALARM SYSTEM WORKS ON THE MOBILE Wireless frequency format 900/1800/1900 Mhz