Gone are the days where drivers are exposed in their cockpits, instead the Halo is now designed to be a first point of contact for an incoming object, rather than the driver's head.
Of course, the Halo was not simply bolted onto the cars at a whim, so let's take a look at how this Formula 1 innovation came to be, what everyone thinks of it, and how successful it has been.
What is the Halo device and who invented it?
There are three connecting panels between Halo and car, one in front of the cockpit where the driver sits, then one either side as the remainder of the Halo structure then circles around the cockpit above the head of the driver.
Simulations from the FIA, Formula 1's governing body, show a 17% theoretical increase in survival chance for a driver thanks to the Halo, with various dangerous scenarios existing where this device comes into play.
In a world of high performance like Formula 1 for example, it is all too easy for drivers to create a shower of debris with the slightest of mistakes, but not even that is needed.
Forces completely outside of their control, like a faulty part or a harsh ride over the kerb, can force components to make a break for freedom.
The Halo, then, is there to protect the drivers from taking a blow to the head from any flying bits and pieces, which also at times can include the cars themselves.
It is a scary sight to see a car tear its way over the top of another, but thanks to the Halo, drivers now have crucial extra protection from any part of that car reaching their head.
Stationary objects can also cause damage to a Formula 1 car and its occupant, namely tyre barriers, walls and even animals on occasion. Once again the Halo is there to save the driver.
The Mercedes team were first to offer up a Halo design, with Red Bull Advanced Technologies putting forward their own version, a transparent 'aeroscreen' which surrounded the cockpit.
The FIA decided to go with Mercedes' concept, not keen on the aeroscreen, while also developing their own version to trial which they called 'Shield', a transparent polyvinyl chloride screen.
Sebastian Vettel was the only driver to ever test 'Shield', ending the run during practice at the 2017 British GP early, after complaining of distorted and blurred vision due to the device, which impacted his ability to drive.
When was the Halo first introduced?
Following tests during the 2016 and 2017 seasons with the Halo device, it was officially rolled out in 2018 as a mandatory feature for all cars in FIA-sanctioned series, appearing in Formula 1, Formula 2 and Formula E as of that season. Formula 3 introduced the Halo from 2019.
The Halo is also compulsory in the FIA's Formula Regional and Formula 4 categories.
However, even some series with no FIA affiliation jumped on the Halo bandwagon, including Indy Lights, Super Formula, Euroformula Open and Australian S5000.
The teams themselves do not produce the Halo, instead the FIA has three external manufacturers of the system to provide the exact same Halo device to all teams.
IndyCar effectively merged the Halo and aeroscreen concepts, with the Halo serving as the frame which the aeroscreen is built onto in that series.
What was the initial reception to the Halo?
In a nutshell, bad.
Before the device had been given its first chance to save lives, Formula 1 in particular was a hotbed for criticism of how it looked.
"This is the worst looking mod in Formula 1 history," commented Lewis Hamilton after seeing Kimi Raikkonen trial the prototype Halo on his Ferrari back in 2016.
"I appreciate the quest for safety but this is Formula 1, and the way it is now is perfectly fine."
Max Verstappen went as far as to say that the Halo had "abused the DNA of F1," after it had made its official debut in 2018.
A large portion of the fanbase were also far from pleased with the Halo from an aesthetic standpoint, which had brought to a close the era of open-cockpit racing in Formula 1.
Nonetheless, what was needed to start changing opinions was examples of the Halo doing exactly what it was designed for - saving drivers from severe injury or worse.
These examples did indeed come.
Which F1 drivers have been saved by the F1 Halo?
Arguably the first clear example of the Halo's benefit in Formula 1 arrived at the 2018 Belgian Grand Prix, during its first season of service.
At Turn 1, Fernando Alonso's McLaren went flying over the cockpit of Charles Leclerc's Sauber, only for the Halo stopping that McLaren from slamming down on Leclerc's head.
Leclerc praised the Halo for potentially saving his life, while Mercedes boss Toto Wolff, who had criticised the invention with a passion up until then, admitted its introduction was "worth it" after ensuring Leclerc escaped unharmed.
Opinions, slowly, were starting to shift.
Skip forward to the 2020 Bahrain Grand Prix and this was the scene where the Halo definitely, not maybe, was responsible for stopping a fatal Formula 1 crash for the first time. The driver owing that eternal debt of gratitude was Romain Grosjean.
After slamming into the barriers, Grosjean's Haas car split into two and became a fireball.
Remarkably Grosjean escaped the wreckage with burns to his hands only, after the Halo had pushed the upper panel of the barrier up so that Grosjean, still in the cockpit, went through the middle rather than his head hitting the metal.
Without the Halo, Grosjean's chances of survival would have been very, very slim.
"I wasn't for the Halo some years ago, but I think it's the greatest thing that we've brought to Formula 1, and without it I wouldn't be able to speak with you today," Grosjean duly acknowledged.
The following season saw the Halo come to the rescue again as Verstappen and Hamilton collided at the opening Monza chicane.
Verstappen's Red Bull was sent on top of the Mercedes by the impact, with a wheel hanging directly above Hamilton in the cockpit. Fortunately thanks to the Halo, it was unable to fully penetrate and Hamilton escaped unharmed. The Halo coming to the rescue of another critic.
Zhou Guanyu is the latest to credit the Halo for ensuring that he is still alive and well, following a truly frightening crash at Silverstone.
A multi-car incident at the start sent George Russell into the side of Zhou's Alfa Romeo, quickly flipping Zhou upside down who skidded at speed into the gravel. As the car dug in, Zhou and his car were sent airborne, clearing the tyre barrier and hitting the catch fencing, then falling in between the two.
Remarkably, Zhou was in full health and raring to get back in the car at the Austrian Grand Prix on the following weekend.
What is the current reception to the F1 Halo?
Very different to the initial reception, that's for sure.
Now into the fifth season of Formula 1 featuring the Halo, its impact on the looks of the cars has certainly weakened, with the device now a very normal-looking feature.
And as for the safety aspect, it is now impossible to argue against the benefits which it has brought to Formula 1.
An early safety fear was visibility, especially due to the panel straight in front of the driver, but that never manifested into a legitimate issue, while the Halo also has not had any kind of negative impact on a driver's ability to quickly exit their car, or the time it takes to extract a driver from the cockpit if needed.
Plenty of the fanbase has also been converted too. Trawling through social media after that Zhou incident, comments like "Thank f**k that F1 introduced that Halo", or "whoever's idea it was to implement the Halo into F1 is an absolute legend", are very commonplace.
The Halo, then, is very much here to stay in Formula 1, and unlike many years ago, you would be hard-pressed to find someone who could advocate with reason that it does not belong in the sport.