Keep'em guessing with this irreverent start button.
This start button will replace most Stern start buttons, some Sega start buttons, some Data East start buttons, all Williams/Bally WPC and WPC-95 start buttons. all Spooky start buttons, and and all Chicago Gaming Company Williams/Bally remakes. 
Basically, if the start button is a 1" diameter lit button then this button will replace it.
Reference numbers 500-6388-44-TL, 500-6388-02, 20-9663-1, and 20-9663-16.