Novelty Item - Brass Boatswain’s Whistle. It Is Also Spelled “bosuns call “This Whistle is Known as The Pipe. It’s a Small Narrow Tube Which Directs Air Over A Metal Sphere (the buoy) With A Hole In The Top. The Player Opens And Closes The Hand Over The Hole To Change The Pitch. Comes With This Elegant Wooden Case With A Brass Anchor Inlay. Truly A Novelty Home Decorating Addition.