Originally posted by Coasterkidmwm
A double horn is when you have two french horns put together in two different keys and you switch between them with a thumb trigger.
It's an unknown standard Holton double horn. I looked up the serial number on the website and it came back as not existing, so my teacher thinks it was a prototype. Pretty much the valves are absolutely tits for the price range (rotary valves are usually awful).
Of course we all want to see a picture of that horn now [:D]