The Boring Company tunnels will fit a Tesla Model X electric car. That's the latest bit of news from Elon Musk's underground adventure.

The company posted a short video (taken vertically...) of a Model X moving through a tunnel on what appears to be the "skates" that propel the car. It's important that the Model X fits because Tesla and The Boring Company boss Musk said the project's transport vehicles will be based on the Model X. The company's plans have shifted from transporting cars and other vehicles on skateboards underground, to pedestrians boarding the electric skateboards themselves.

We don't know how fast the Model X was going in the video, but The Boring Company shuttles will supposedly be able to travel at speeds between 120 mph and 150 mph.

It's unclear what tunnel is shown in the video. It could be the first test tunnel at the company's headquarters in Hawthorne, California, or it could be a newer tunnel in Los Angeles close to Interstate 405 and the airport.

Before the public can climb aboard for Musk's proposed free rides, The Boring Company will need regulatory approval. Eventually, thousands of stations could litter Los Angeles, and the cost could be less than a bus ticket. The solution was first envisioned to resolve LA's horrendous traffic congestion, but Musk's idea is spreading. Last week, The Boring Company received the green light for a tunnel line from downtown Chicago to O'Hare airport., and the company has received permission to dig a 10-mile tunnel along the Baltimore-Washington Parkway. With the Chicago announcement, the cost of a ride was estimated to run between $20 and $25.

The video is now the second time we've seen a real-life vehicle fit inside one of the tunnels. Last August, Musk posted photos to Instagram of a Model S electric sedan inside of the same tunnel. But, that was when Musk originally wanted to simply transport cars on electric sleds—not pedestrians in the electric skateboards.