The trade advertising of the time was a challenge to distributors: Be the first importer on your market of the worlds smallest roundwatch!". The Ladybird was born in 1956 when the fashion was for jeweled watches in which the emphasis was on ornamental features and dainty dial sizes. Within this context, Blancpains unveiling the worlds smallest round movement, the R550 caliber, was a true masterstroke. Notwithstanding its 11.85 mm diameter, this movement had a more than 40-hour power reserve that was quite extraordinary for the period. For aesthetic reasons, its crown was re-located to the back of the watch. As for the pivot placed above the escape wheel, it was slightly thinner than an average strand of hair, at just 0.07 mm."