Long before James Bond's ingenious cigarette gun, ski pole gun, and yes, even bagpipe gun -- there was the real-life "Le Petit Protector."
Scarcely larger than a fingernail, this unusual 19th century pistol was mounted on a metal band and worn on the finger, much like a jeweled ring.
Now a rare Protector, believed to be one of the world's smallest guns, goes to auction this week.
Featuring a 4mm six-shot pinfire cylinder, the French firearm is expected to sell for up to £1,300 ($1,840) on March 18, according to online auctioneers Catawiki.
"This rare piece is a spectacular show of craftsmanship and undeniably intriguing," said auctioneer Alain Dilmen.
"Lots such as this rarely come to auction, and with this gun being so unique we expect to see an influx of bids from across the globe."
Presented in a red velvet-lined case, the miniature revolver was perhaps historically used more as a deterrent, than as a fatal weapon.
Generating less force than a modern-day pellet gun, the Protector can penetrate one side of a tin can -- though that's about the extent of its firing power, according to industry website guns.com. The ring gun dates back to an era of many imaginatively concealed personal pistols -- from the walking stick rifle to the single-shot pen gun and pocket-sized derringer.