Pirelli has kickstarted a two-day Formula 1 test at the Paul Ricard circuit in France aimed at improving the wet-weather performance of its tyres.
Ferrari, Red Bull and McLaren have agreed to take part, with Kimi Raikkonen, Daniel Ricciardo and Stoffel Vandoorne respectively in action on day one.
Sebastian Vettel and Daniil Kvyat will take over on day two for Ferrari and Red Bull, with Vandoorne to continue for McLaren.
All three teams are using their 2015-specification cars, with no modifications allowed.
Red Bull is running a slightly modified livery now it no longer has sponsorship from Infiniti, with the words 'Red Bull' on the sidepod rather than the car manufacturer.
With trackside sprinklers on hand at Paul Ricard to douse the circuit at any given time, it means Pirelli has ideal and guaranteed conditions to conduct its testing.
Pirelli motorsport boss Paul Hembery recently told Autosport one area of Pirelli's focus at the test would be on the aquaplaning performance of the tyres.