The Knightsbridge Wireless PIR Sensor Door Alarm in white offers a detection range of 8 metres and a transmission range of up to 100 metres. It operates on Wi-Fi and battery power, with a transmission frequency of 433MHz +/- 0.5MHz. This door chime features 36 different chimes/melodies, adjustable volume of 80db, and a visual indicator with an LED. Easy to use and install, this alarm system is ideal for home security and can be connected wirelessly for convenience. Made by Knightsbridge, it is a reliable and efficient choice for protecting your home.