A design student has created what might be the lightest running shoe ever made.
Luc Fusaro, who is also part of the team which designed the London 2012 podium, made the shoes while a student at the Royal College of Art in London.
The shoes are custom-made for each athlete, and are produced using a 3D printer.
Weighing just 90 grams, they are among the lightest ever made.
Fusaro thinks they could be ready for competition by the 2016 games in Rio - and even the current prototypes could shave fractions off a 100m time.
"The current mass-manufacturing process only allows to produce shoes with standard mechanical properties and geometries," his website explains. "Using the opportunities offered by additive manufacturing... opens up the possibility of whole new generation of athlete-specific footwear."
French-born Fusaro previously studied General Engineering at Ecole Centrale Lyon - but also competed in athletics "at a national level" for a number of years.
More fine-tuning is needed - the upper part of the shoe is reportedly too stiff and more comfort needs to be added. But Fusaro said they still showcase the "unlimited potential" of 3D technology.