A Royal Navy Bosun's whistle for sale.  The WW2, Royal Navy whistle in nickel-silver with 'Made in England' impressed to the keel, and  War Department arrow impressed to both sides of the buoy.

Condition report: Excellent overall condition.

Note: A boatswain's call pipe or bosun's whistle, as it is more commonly referred  is a pipe or a non-diaphragm type whistle used on naval ships by a boatswain. It is pronounced, and sometimes spelled, "bosun's call."

The pipe consists of a narrow tube (the gun) 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.

The rest of the pipe consists of a 'keel', a flat piece of metal beneath the gun that holds the call together, and the 'shackle', a keyring that connects a long silver or brass chain that sits around the collar, when in ceremonial uniform.