Motorcycle horn, make "Cicca", Paris. Probably from the 1930s.
The unit is fixed to the motorcycle fame end a cable needs to be pulled so that the rubber drive wheel engages against the motorcycle tyre.
Appears to be mechanically complete but I have not had it installed on a motorcycle so I have not been able to verify that it works...
Original Factory publication issued by Ettore Bugatti 1-3 Brixton Road London.
Size: 215 x 280mm approx.
Slight crease marks, but overall good and clean.
Postage charged as cost.