The Geiger counter watch that James Bond used in 1965's Thunderball has been discovered at a UK car boot sale, and will be sold at Christie's on June 26.
The watch is the first that gadget man Q adapted in the Bond series, marking a landmark moment for watch collectors.
After being bought for just £25, it is now expected to realise between £40,000 and £60,000 ($60,822-91,233).
Made by Breitling in 1962, the Top Time watch was then adapted for use in the film by the James Bond art department.
One of its hands was modified to show the strength of radioactivity, a crucial tool in finding the two NATO bombs stolen by SPECTRE.
It is thought that the watch was passed on to one of the crew at Pinewood Studios (which is where Thunderball was produced) shortly after filming. However, it is not known how it eventually made its way to the car boot sale.
In March, a Rolex Oyster Perpetual that belonged to a James Bond cameraman and adventurer was offered with Anderson & Garland.
Bond is famous for his gadget-filled watches, with the magnetic Rolex Oyster Perpetual Submariner taking pride of place at number one in our top five Rolex watches.