The 31-121.022 is a single-pole single-throw illuminated Pushbutton Switch with soldering (also pluggable 2.8 x 0.5mm) terminals, momentary action, 1NC+1NO contact type. The illuminated pushbutton is equipped with snap-action switching elements. Besides the standard contacts (gold-plated silver) silver contact for switching elements 2.8mm plug-in terminals can be supplied. All switch actuators are mounted from the front by pushing them through the mounting hole in the front panel. The illuminated pushbutton equipped with diodes, the user is able to perform a lamp check or wire an alarm circuit simply with a considerable saving of space.