A Ooogah 12 Volt Horn Old Model A Chrome Horn. Don't tell me you don't remember this! It is just over 9" long and the end of the bell is about 3 1/2". This is a 12 volt reproduction of an old classic.  I cheated a little and didn't use a separate horn button. Just a toggle switch so I could select which horn and use the stock horn button. Works slick. The bell is chrome plastic but holds up very well.