Elon Musk has begun retooling Tesla facilities to build ventilators for the Covid-19 crisis and a new video shows how it's being done.

Tesla engineers explain how they've managed to repurpose their facilities and components to build much-needed ventilators which will help the medical industry without taking away from their supply. Watch it below.

Elon Musk came under fire after he claimed to have “extra FDA-approved ventilators” ready to ship out last week. Forbes reported that the 1,000 units the company shipped weren't the right kind. Rather than the vital ventilators needed to help coronavirus patients breathe, Tesla delivered breathing devices for homes for ailments such as sleep apnea.

An NPR story also suggested that the machines Musk donated actually exacerbated a coronavirus outbreak in a Washington nursing home. The machines may have pumped the breath of infected patients into the air where it could then be inhaled by staff and patients in a phenomenon known as aerosolization.

The Tesla CEO also faced criticism for his decision to continue operating his Tesla plant amid the coronavirus pandemic. However, while Tesla isn't complying with the “shelter-in-place” measures to curb the spread of the virus.

Musk claims his electric car company will still work to help in this critical time, however now Tesla is joining automakers including Ford and General Motors in building the ventilators using their own resources.

Musk initially made the pledge on Twitter in response to a fan who asked him to repurpose the Tesla factory to make ventilators that are needed. Many people suffering from COVID-19 need to be connected to one to help them breathe while they recover. The Tesla CEO responded: "We will make ventilators if there is a shortage."

Journalist Nate Silver responded to Musk, claiming "there's a shortage now." To which Musk said "Ventilators are not difficult, but cannot be produced instantly. Which hospitals have these shortages you speak of right now?"