It was designed in the way that the projecting part of
the button would fit all kinds of small furnaces and control boxes.
The operating part is injection-made of acryl mixed resin,
being highly clear and provicing a wide range of chooices
of colors from red, green, yellow, white, blue.
(Cutting hole size 25Ø / Contact point 1a1b / AC 250V 8A)