Push buttons open and close contacts by force applied by the finger to the operating component in the vertical axis direction. Push buttons consist of the operational component that transfers external force to the switch, the switching component that opens and closes the electrical circuit, the mounting component that grounds the switch and fixes it to the panel, the light source that indicates operational status, and the casing that protects the interior components. LED illuminated push buttons come with the LED light source that is built into the operational part and cannot be taken out; push buttons with incandescent lamp illumination have independent operational parts and light source that can be separated. Non-illuminated types do not come with a light source. Button light colors include green, red, orange, etc. Switch function styles include momentary, where the pressed button returns to the initial position once it is released, alternate action, where the first push maintains the operational position, which is then disengaged with a second push, etc.