Reigning world champion Lewis Hamilton has made his views clear about F1's plans to push ahead with more cockpit protection next year.
Ferrari has been testing an early prototype of the Halo device this week, which is designed to deflect big objects away from the driver's head.
Hamilton posted a picture on Instagram of Kimi Raikkonen running the modification on Thursday, saying: "Please no! This is the worst looking mod in Formula One history. I appreciate the quest for safety but this is Formula One, and the way it is now is perfectly fine."
Hamilton has spoken out against upcoming changes to the regulations, saying he longs for a return to the cars of the 1980s and 1990s. His criticism of Halo came on the same day his team-mate Nico Rosberg praised the idea as a potential life saver.