Joe Biden has long been an advocate of wearing masks to stop the spread of COVID-19. It's a habit so ingrained for the President-Elect that he's often seen sporting two at once.
So why does the next POTUS double down on the facial fabric?
The exact reasons why Mr Biden wears two masks at once remain unclear, however the habit has been snapped several times at key events and clocked by US media.
In his first official outing since being called as the next President by US media, Mr Biden was seen wearing a sombre black mask on Veteran's Day with a white surgical mask peeking out from underneath.
He also appeared to be doubling up while speaking to reporters on election day, and has been pictured wearing a medical mask underneath a cloth version on the campaign trail.
At the ABC News Town Hall debate in mid-October he addressed the issue when saying that the words of a President matter when it comes to protecting oneself from COVID-19.
"When a president doesn't wear a mask, or makes fun of folks, like me, when I was wearing a mask for a long time, then people say, well, it mustn't be that important," he said on stage.
"I think this is very important -- for example, I walked in here with this mask, but I have one of the N95 masks underneath it. And I left it in the … dressing room."
"If you listen to the head of the CDC, he stood up, and he said, you know, while we're waiting for a vaccine -- and he held up a mask -- you wear this mask, you will save more lives between now and the end of the year than if we had a vaccine, than if we had a vaccine.
"It is estimated, by every major study done from the University of Washington to Columbia that if, in fact, we wore masks, we could save between now and the end of the year 100,000 lives."
The US CDC notes that the SARS-CoV-2 infection commonly known as COVID-19 is "transmitted predominantly by respiratory droplets generated when people cough, sneeze, sing, talk, or breathe."
It recommends using masks in the community to prevent transmission of the virus. They work by reducing the emission of droplets from a potential source who may be unaware they are infectious – which is estimated to account for around 50 per cent of transmissions.
They have the secondary benefit of protecting the wearer by filtering what they breathe in through the nose and mouth.
The World Health Organisation also advises wearing masks along with social distancing, avoiding crowds, washing hands and other measures under their "do it all" approach to controlling the virus.
It states those over 60 (Biden is 77) are deemed in a vulnerable group and should be sure to wear a medical or surgical mask rather than a simple cloth version.
Whether Biden's decision is out of an abundance of caution or the feeling that two is more protection than one is not known, his team have not commented on the decision.
However it may have already provided benefits after he didn't need to quarantine after taking a charter flight with a person who later tested positive for the virus. The Democrat was not deemed to be a close contact and wore his mask throughout the flight.
It may be that he didn't want to risk having to quarantine in the final stages of a crucial campaign – which may have paid off given the fact many of the upper echelons of the Trump administration, including the President himself, were forced to isolate after contracting COVID-19 possibly at a White House event.
Medical experts have told US media that wearing two masks doesn't necessarily offer more protection when they are of the medical variety. In fact, it could require extra care not to contaminate both.
However it could help in the case of cloth masks where generally speaking, "the more layers the better," Tania Elliott, M.D., an immunologist and allergist at NYU Langone Health, told SELF.
Either way, it seems mask wearing could become more common in the US after the President-Elect appealed to Americans to wear them to tackle the public health crisis that is still spiralling out of control.
"We could save tens of thousands of lives if everyone would just wear a mask for the next few months. Not Democratic or Republican lives. American lives," he said.
"I implore you. Wear a mask. Do it for yourself. Do it for your neighbour. A mask is not a political statement."
The Biden-Harris transition website states his team plan to bring in nationwide mask mandates by working with governors and mayors around the country.
"President-elect Biden will continue to call on: Every American to wear a mask when they are around people outside their household," the team said.