NOT Touch! This is contactless Switching.
The use of optical IR sensing:an optical signal is emitted, hits an object, is reflected and then detected.
Touchless switches are used wherever increased hygienic requirements for triggering door openings are demanded. is highly demaned in home automation.
But also in public restroom facilities, from door opening to triggering the toilet flush and hand wash faucet, everything can be actuated without contact. In residential and care facilities, especially for people with limited mobility, they make life a lot easier.
An interesting application is also the door opening for the service staff in the catering trade between kitchen and guest zone, where often no hand is spare.
Sensing distance is 0.1-10CM, Pin assignment is 12V/GND/COM/NO/NC