Tesla boss Elon Musk has announced that his company will finally reveal its first electric tractor-trailer truck this September. He said the vehicle is “seriously next level” and noted that the team behind it had “done an amazing job.”

Back in July 2016, Musk revealed the second part of Tesla’s “Top Secret Masterplan” - the first part, announced in August 2006, was the mass production of the Tesla S and Tesla 3. In addition to plans for a “solar-roof-with-battery-product” and the upgrading of Tesla’s semi-autonomous Autopilot into a completely self-driving system, Musk said he wanted to expand the company’s line of vehicles.

The Tesla semi will reduce the cost of cargo transportation, as well as increase driver safety, according to Musk. In its 2016 Q2 earnings report, he said the Tesla Semi and a Model X-based Tesla minibus would be unveiled in 2017, part of the company’s overall goal to “expand to cover the major forms of terrestrial transport.”

There was also mention of a Tesla pickup truck model last year. It’s now been confirmed by the CEO that this will be shown off in 18 to 24 months. While answering questions from other Twitter users, Musk revealed that the next Tesla Roadster sports car would be a convertible.

A number of companies are pouring resources into electric truck development. The Nikola Motor Company unveiled its gas/electric powered big rig last year, which can generate 2,000 horsepower and 3,700 foot-pounds of torque with an estimated range of 1,200 miles. A few months later, Mercedes-Benz showed off the Urban eTruck, which can carry loads of up to 29 tons. Over in Sweden, meanwhile, there are electric highways that power trucks using overhead lines.