The DEI 506T is a very effective and small sensors that is reliable and will give you very good protection unlike many others on the market. Some of the ways vehicles are targeted a shock sensors will not always trigger due to how a window is smashed or the door can be bent back which means a glass break sensor will give you a much higher chance of your system triggering when the glass is cracked or smashed in an attack. The audio sensor is very small and can be mounted on the bracket that comes with the system or it can be drilled and flush mounted on to a surface. A glass break needs setting up correctly when its installed and when it has been set up it should never need adjusting again unless the audio sensor location is moved.
The glass break sensor can also be added to many types of security systems by cutting the DEI plug at the end of the plug and manually hard wiring the sensor on a car alarm of your choice. Providing the alarm accepts a negative input you will be fine. It uses a very low voltage and it will last for many years.