You’d have to look under the grille and see what’s under it. If it’s http://www.dan.calvinet.com/Simplex_4903-9405.JPG shiney and silver, it’s an electromechanical horn. If it’s black with a little reflective piece in the middle in the shape of a circle, it’s a speaker. And if it looks black with silver stripes along the top and bottom of the grille, it’s an electronic horn. I own all 3 versions, but the link to the one above is the only best shot I have.
