S 311 B13 TX is part of the Legrand Sience range of digital timer switches. This switch is an electronic switch for controlling lighting, heating, and ventilation in residential and commercial spaces. It can be set to turn lights and other devices on and off automatically at pre-set times, and includes adjustable functions like daylight savings time, push-button override, and manual override, and the ability to be used with all types of switches, including dimmer. It also includes a built-in protection system to protect against surges, lightning strikes, and overcharging.