Devices that warn you before intrusion of the possible attack or intrusion are no less vital than the direct contact weapons like the pepper spray and stun guns. In many cases it is even better than the traditional warning devices or weapons. The advantage is that once you are aware of the possible danger, you can be in readiness to protect yourself or to take measures that would prevent the attacker from doing what he wants. Even the use of products and weapons will become far too easier with such warning devices as you get time to prepare yourself. 

Door has always been the first line of self defense for any person. Door stop alarm is therefore a first line of defense for any person. Ordinarily, they are designed to fit in the door sop wedge. The device is normally place behind the door and whenever the door is opened, it gives out a loud pulsating alarm.  

The alarm will go on even if the unit is moved or the door is opened. Thus, this alarm is an effective tool to block a door from being opened. The volume of alarms sound is 125 decibels. The device is more like the mace alarm & flashlight.

Door stop alarm runs on a 9-volt battery. There is an on/off switch, which could be used to turn off the device when required. The gadget is economic at only $14 and is cheaper than the Video surveillance camera.