UB Illuminated Pushbutton with Protective Guard NKK Switches UB Illuminated Pushbutton with Protective Guard is a Single Pole Double Throw (SPDT) illuminated pushbutton with a snap-in panel mount module. This illuminated pushbutton switch features silver contacts, a white diffuser cap with green LED illumination, and a solder lug that facilitates quick connection. The UB illuminated pushbutton with a protective guard offers a full-face illuminated cap with a spring-loaded polyamide protective guard. This spring-loaded protective guard opens to 180° with an automatic close function.