CPE ELLIPSE electronic time lag switch.10second - 20minute

CPE ELLIPSE electronic time lag switch.10second - 20minute also known as a staircase switch fitted on each floor of a communial staircase instead of a conventional on off switch. 

These electronic switches can replace the old vacuum type push switches with the advantage over the pneumatic that they do not wear out through years of use causing the timing on the vacuum to reduce untill it will not time at all. NO NEUTRAL REQUIRED

Then the alteranative was to jam the vacuum push with a matchstick to keep the lights on until the person reached their floor, unfortunatley this then holds the lights on continuously defeating the purpose of the time lag switch.