Schurter Touchless Hidden Switch (THS) Metal Line Switches are innovative switches with optical sensor technology that can be concealed behind any surface without the need for mounting holes. A small opening in the user interface is all that is needed to allow the time-of-flight (ToF) sensor to actuate. Schurter THS switches allow for free design, invisible installation, and a small mounting depth. These touchless pushbuttons also offer multicolor illumination.