you mean the one that has a control panel that will ring several phone no's with a recorded message? I saw it on special offer at Ironmongery Direct at £129. List price is about £200.
http://www.ironmongerydirect.co.uk/...Protection/7194/Yale_Premium_Alarm_Kit/825434
It's the best of the Yale alarms. People will tell you a hard-wired alarm is better, and no doubt it often is, but the Yale is very quick to install and you can have it working in an hour or two.
My tip is to set the siren for a one-second hoot for the first day or two, while you get used to it, to avoid annoying the neighbours with false alarms which will cause them to ignore it.
It is absolutely vital to put the control panel well away from a potential entry point, to prevent anyone yanking its wires to prevent it phoning out or, smashing the panel while it is in count-down, before the siren starts. once the siren has started, smashing the panel will not stop it.
You can put a extra keypad near the front door to set and unset the panel.
You can add up to 20 sensors and aditional sirens to it. The series 3000 parts are fully compatible with the 6000 series, but not so easy to use as they do not have a test button on the outside. The cheapest way to buy additional sensors and a siren is to buy the more basic alarm kit with no panel.
Allow for reading through the manual first and watching the DVD a few times so that you understand what you are doing.
Put the siren where it is easy to see but not easy yo reach. Sometimes you can put it where you can reach it through an outside window to change the batteries after two or three years.