It is hard to imagine life before car alarms, but now, nearly every car is guarded with car alarms, and these devices have become indispensable in reducing the number of car thefts per year. Car alarms are designed to warn the thief, bystanders, and the car owner, and there are many types of car alarms designed for different purposes. The most common type of car alarms will ring if the door or the hood is disturbed. Sometimes, these car alarms can sound for quite some time, but can easily be turned off by the owner once it starts to make noise.

Many car alarms work with sound, but others also have flashing lights, which are also useful for alerting the owner or bystanders at night. Car alarms should sound at a high frequency so they can be heard and startle the potential thief. Many of these car alarms are operated by a 3 button remote which can fit in the palm of the hand. As the owner leaves the car, the alarm can be turned on or shut off, if the owner is within range. Most car alarms are set off if the door, hood or engine is disturbed. Some are highly sensitive, and can go off at unwanted times, but this is preferable to car alarms that do not work efficiently, since it is simple to shut them off.

Some car alarms do not make noise and alert the thief, but alert the owner of the car that the door or the engine has been disturbed. These pagers will let you know that someone is getting into your car or that the engine is running. You can then notify the police immediately. Some people prefer the pagers to the traditional car alarms, because they lure the thief into a false sense of security and make it more likely that he will get caught. Others believe that traditional car alarms can prevent the crime before it happens.