Silver Ships Bosun Call Boatswain's Whistle with Wood Gift Box Great conversational piece, this Silver Ships Maritime Boatswain Bosun Whistle Pipe Boatswain's Call or Bosun Whistle used throughout history by the Navy, consists of a narrow tube which directs air over a metal shape and a hole in the top Most notably used by Senior Crewmen to pass commands on a Navy ship, the user opens and closes their hand to change the pitch Bosun Call measures 4 3/4" long and 1 1/4" wide, with a 21" long chain, and comes in it's own Wood Gift box which measures 5 1/2" long, 1 3/4" wide, and 1 3/8" tall Silver Ships Maritime Boatswain Pipe Bosun Whistle Call with Wood Gift Box ships brand new with our 100% customer satisfaction guarantee