Halo
The halo is the titanium structure arching over the cockpit, mandatory in Formula 1 since 2018, designed to deflect debris and withstand an impact many times the car's own weight.
It was unpopular on introduction, largely on looks, and that argument ended quickly. It is widely credited with saving Romain Grosjean at Bahrain in 2020 and Zhou Guanyu at Silverstone in 2022, among others.
It is a single piece of titanium bolted to the survival cell at three points, and it is strong enough to support the weight of a London bus.