Shares of Lightning eMotors (NYSE: ZEV) have exploded over 70% in today’s market session after the company reported it agreed on an $850 million deal to sell 7,500 zero-emission shuttle buses to Forest River, owned by Berkshire Hathaway (NYSE: BRK.A).

The agreement will see ZEV build fully electric buses, as well as provide charging products and services to Forest River by the end of 2025.

“This has the potential to be the largest contract ever in the electric shuttle bus market, and we believe it will be the catalyst for other large commercial vehicle OEMs and fleets to accelerate their adoption of commercial electric vehicles,” said Tim Reeser, CEO of Lightning eMotors.

“Forest River’s family of shuttle bus companies, including top name brands like Starcraft, Glaval, and Champion, maintain a dominant market position selling over 10,000 units per year in the Class 4 to 6 shuttle-bus space.”

Forest River is considered to be the market leader in producing shuttle buses in North America thanks to its eight plants. Co-produced buses will have battery configurations from 80kWh to more than 160kWh.

“We decided to work with Lightning eMotors after several years of extensive research because of their market and technology leadership in the commercial EV segment. I was especially impressed after visiting their manufacturing facility in Colorado, driving their vehicles, and talking to their customers. It is clear why Lightning eMotors is at the forefront of fleet electrification,” commented ” David Wright, president of Forest River’s bus divisions.

Buses will be built in ZEV’s Colorado facility before being shipped to Forest River’s factory in Indiana for final assembly.