Require no mains power and use Liion batteries that can last 3 years.PIR Radiowave sensors - no wiring and are very quick and easy to install.
No power point required from client. These are the same as a wired PIR and are powered by battery. They are very useful to use when there is a difficult/unsafe cable run. They are also useful on demolition sites as cables tend to get chopped and sites with no power. The Dual frequency radio waves are used to prevent jamming that can occur using a single frequency. It also extends the range to an impressive 500m clear line of site. Practically, in cities, they will work up to 100m, site tests should be carried out.