Rivian on Thursday released a short video showing pre-production R1T electric pickup trucks being assembled at its Normal, Illinois, factory.

These pre-production vehicles will be used for final testing, and won't be sold to customers. Rivian doesn't expect to start deliveries of the R1T June 2021, with the R1S SUV version following in August 2021.

That's a delay of six months from when they were originally due. Rivian previously said it was forced to delay the launch schedule due to the coronavirus pandemic and its effects on readying the factory, which is a repurposed former Mitsubishi facility.

Rivian already provided a walkthrough of the factory last month, but this latest video gives a sneak peek that many of the R1T's distinctive features in concept form—like its headlights—have made it through to the production version.

The original R1T concept was unveiled at the 2018 Los Angeles Auto Show, where Rivian also announced some impressive specs for the production version. That included a maximum range of more than 400 miles, 0-60 mph in 3.0 seconds, and an 11,000-pound towing capacity.

Rivian uses a "skateboard" platform that contains the battery pack and all mechanical components, allowing different bodies to be easily engineered for the platform. The same skateboard underpins the R1S, and will be used for electric Amazon delivery vans and at least one Ford model.

Amazon and Ford have both invested in Rivian, which has raised $5.3 billion since 2019. That's given the automaker a budget that suggests logistics, suppliers, and people are the limitation in getting its first vehicles into production—not money.

Earlier this summer Rivian moved more of its workers from Michigan to California, for vehicle development and tech, and to the Illinois factory.