The all-electric big rig that Tesla has been developing will travel 200 to 300 miles on a single charge, according to a new report from Reuters. Tesla is slated to unveil a prototype of the semi truck at an event in September, though a specific date has not been revealed.

The information about the truck’s range appears to come from Scott Perry, an executive at Ryder, a fleet operator based in Florida. Perry told Reuters that Tesla is focused on “an electric big-rig known as a ‘day cab’ with no sleeper berth, capable of traveling about 200 to 300 miles with a typical payload before recharging.” Perry did not respond to a request for comment from The Verge in time for the publishing of this story.

It’s certainly possible that Perry has seen the Tesla truck, or the company’s plans. In June, Tesla CEO Elon Musk mentioned during a meeting with shareholders that the company was gathering feedback from the trucking industry.

That’s far less range than combustion engine trucks, which some experts expected

“We’re getting them closely involved in the design process, so the biggest customers of the heavy duty Tesla semi are helping ensure that it is specified to their needs, so it’s not a mystery,” Musk said then. “They already know that it’s going to meet their needs, because they’ve told us what those needs are. So it’ll really just be a question of scaling volume to make as many as we can.”

While 200 to 300 miles of range is considered plenty for an electric sedan or an SUV, it’s two to three (or more) times less than how far semi trucks with combustion engines can make it on a single tank of diesel. And ever since Musk has been talking about making an electric tractor trailer, experts have wondered openly about how much battery capacity could be squeezed into the form factor before the technology became too expensive to justify the idea. “I’m not going to count them out for having a strategy for longer distances or ranges, but right out of the gate I think that’s where they’ll start,” Perry told Reuters.

When reached for comment, a Tesla spokesperson offered the same comment given to Reuters: “Tesla’s policy is to always decline to comment on speculation, whether true or untrue, as doing so would be silly. Silly!”

Tesla’s truck is also apparently going to have self-driving capabilities, according to a previous report from Reuters that uncovered emails between the company and the Nevada Department of Motor Vehicles.