These are known as Audible only or bells-only alarm systems.You set your alarm by entering a code, to deactivate the alarm you should enter the code again or some systems provide keys. You need to insert key and turn it on/off.When the system is triggered by an intruder, it will trigger sounders that are mounted on the external walls of your building. To stop the noise someone needs to enter the correct code or insert key to turn it off.
These Burglar Alarm Systems are best for
• A visible deterrent to opportunist thieves
• Making a noise to scare off an intruder
• Waking you up if you’re at home and someone tries to break in
• Making neighbors aware of a break-in
Advantages
• The loud noise and attention it attracts is likely to scare off a chance intruder
• Battery back-up in external sounder means it keeps ringing even if the mains connection is cut.
ATSS Products Active 108,Active 207,Active 306 comes under bells only alarm systems,but if you wish to get alarm alerts to your mobile,There is an Provision available in all three mentioned systems to attach an auto dialer.