The Elkay Ceiling Mount PIR Occupancy Sensor is an energy saving device to switch loads only when there is presence detected. This PIR timer unit has been specifically designed for ceiling mounting and includes spring fixing arms for quick and easy installation. This compact unit is one of the smallest most discrete units available and can be flush or surface mounted when used with a surface mounting box. It can also be mounted on BESA boxes. The PIR is a time switch designed to sense moving infra-red such as moving body heat, and activate a load or appliance for a specified time period. An internal light sensor will keep the load switched off when sufficient ambient light is available. A red indicator LED signifies when timing has been re-triggered and when the unit is in its final minute of countdown.