A clicker from the D-Day landings has been found after an appeal to commemorate the 75th anniversary of the Allied invasion of Normandy.
About 7,000 of them were made by ACME whistles in Birmingham in 1944 who said "very few" had been seen since.
Following the appeal, one was found in a drawer by a soldier's daughter a "stone's throw" from where it was made.
It belonged to Geoffrey Kemp Bond, a teacher from Watford, who served as an army captain during World War Two.
Mr Bond's daughter, Liz Campbell, found the clicker while sorting through the serviceman's possessions but said she did not realise "how rare" it was.
American paratroopers, dropped behind enemy lines, used them if they detected someone nearby in darkness.
Two clicks in response to one meant it was a friend.
Mrs Campbell knew her father served in Normandy during the landings but said she did not know how he came by the clicker.
"My father was an avid collector and interested in history," she said.
"Keeping military items would have appealed [to him], with the view of saving a piece of history."
ACME Whistles was founded in Birmingham in 1870.
The manufacturer appealed to find any remaining clickers, to commemorate the 75th anniversary of the D-Day landings on 6 June.
They were hoping to "unearth a lost piece of sound history", the company's managing director, Simon Topman, said.
"Little did we know that we'd find one so close to the factory in Birmingham."
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