The new 2017 Mercedes W08 Hybrid is back in action at pre-season testing at the Circuit de Barcelona-Catalunya this afternoon, only this time it's sporting a new addition in the form of a proper 'shark fin'.
The shark fin is a new feature of this year's Formula One cars as a result of the new tyre and downforce regulations that have been brought in over the off-season.
However Mercedes left the full fin off the car when it was photographed for its official launch, and it was also absent when Valtteri Bottas took the new car for its first test laps on Monday morning.
With Lewis Hamilton taking over the wheel for the afternoon session, the team has now installed the complete shark fin to compare it with the earlier running times to see what impact it makes.
Already back in action in the afternoon is Kevin Magnussen, after repairs were made to his Haas VF-17 following an accident at turn 12 just before lunch which damaged his front wing.
Daniel Ricciardo has also taken to the track, this afternoon having losing track time in the morning with a sensor issue on the RB13.
Meanwhile Honda has decided to change the engine in Fernando Alonso's McLaren which suffered an oil leak on its very first installation lap. The team says that changing the unit will save time overall.