Apple Inc. is designing face shields for medical workers and has sourced over 20 million masks through its global supply chain, Chief Executive Officer Tim Cook said on Twitter.

Sunday's tweet says that Apple's design, engineering, packaging and operations teams are working with suppliers to get the shield made and shipped. This new product was created by Apple designers and produced by Apple and its suppliers.

Apple designed a transparent plastic face shield that packs flat and assembles in less than two minutes.

Apple is sourcing materials and manufacturing in both the U.S. and China, Cook said, saying that Apple was focusing on unique ways to help “at a scale the circumstances require.”

The first shipment was delivered to a Santa Clara, California, hospital last week. The shields are fully adjustable and assemble in under two minutes, Cook said, adding that Apple plans to ship over a million this week and another million weekly after that.

Apple has shuttered all 458 of its retail stores outside of China to curb the spread of the Covid-19 pandemic and is requiring its engineers and designers to work from home.