A B C's Matt Gutman, now on the grounds of one company in California where they are working intensively toe add to the nation's stockpile.

We're hearing Bloom energy and what you're seeing here.

These are basically ventilators from the federal government, the boxes, the Pelican cases.

They're empty right now because all of them are being checked here by technicians now, remarkably, this company actually manufactures fuel cells, so they don't really do ventilators.

But they are engineers and mechanics, and he downloaded from Google the instructions on how to make these things work and basically figured out an assembly line.

And that's what you're seeing here.

Batteries are being taken out because 200 that were delivered the vast majority were faulty, not broken, but faulty batteries weren't working.

Those 200 came from the federal government Strategic National Stockpile.

Now what's so interesting about them is that they're small.

It always thought that they would be these big rigs rolled in on carts, but these are actually backpack sized ventilators now.

Ventilators, as we know, are the only proven treatment toe work to help patients who are suffering from Cove it 19.

They actually sell simulated lungs on the market, but you couldn't find any, so you got very hard to get.

These days, we found that the punching balloons give us the same result.

They work this for an hour to make sure that they can deliver air into simulated lungs.

And according to Joe, typically the balloon punching bags give way before the machines, which is a good sign they're put into boxes.

If anything is missing, it's annotated, and then they're shipped out and they go back to hospitals.

One more disconcerting thing that we just learned overnight officials here warning off a surge that could make parts of the state, especially like Los Angeles, look like New York in just a few days time.

All right, our thanks to a B C's Matt Gutman.

Hi, everyone, George Stephanopoulos here.

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