Flapper for Exhaust

[Soundguy]

More likely it would be classed as a 'destructive device'.

Soundguy

 

[Redbug]

Boy, you guys really got way-laid off the main subject! Tennis ball shootin' Hah! Look at what fun these folks are up to...pumpkin chunkin'. Can't beat livin' in good ole' America!

http://www.cannon-mania.com/pumpkin_chunkin.htm