Horn Packaging

I bought a low-tone horn of my car. But do not realize it takes 24 volts till I opened the package. As this was a final sale, I can not go back (was only $ 2.50). Now I know the dough in my truck is 12V, if I can use this horn is it? What are the symptoms of tension provided too little?

Can I somehow increase the voltage? As through a simple circuit?

Think this should work but with fewer decibels.