The Echoflex Photo Sensor TAP-31 is a wireless, self-powered photo sensor designed for indoor use. It provides a reliable and simple method for increasing energy savings by adding daylight harvesting capability to your Echoflex lighting control system. With two selectable ranges – 0-1024 lux (95 fc) and 0-65535 lux (6090 fc) – the TAP-31 is perfect for open- or closed-loop daylighting applications.