Tesla Motor Inc.’s (TSLA) new Semi heavy duty trucks are on the road with their first cargo trip, marking another milestone for the electric carmaker.

CEO Elon Musk posted shots of two Tesla Semis getting ready to depart the Sparks, Nevada facility with a shipment of battery packs from the company’s Giga factory and make their way to Tesla’s auto plant in Fremont, California.

The all-electric trucks reportedly have the ability to drive 500 miles on one charge and carry a maximum load of 80,000 pounds. They can maintain a speed of 60 mph on a 5 percent grade incline, or about 20 mph more than the average diesel truck. (See also: Tesla’s Electric Truck Meets Early Success.)

Tesla unveiled the trucks in November, touting their money-saving features and ability to go from zero to 60 mph in less than 5 seconds. Since then, the trucks have been spotted without their trailers on the route from Sparks to Fremont. Mass production is not expected until 2019.

So far, Tesla has already received preorders for the trucks from major corporations, including from big box retailer Walmart (WMT). Beverage giant ABInBev reserved 40 Tesla Semis for $5,000 per reservations. J.B. Hunt Transport Services Inc. (JBHT) also has reservations for “multiple” trucks. (See also: Why Tesla’s Stock Can Soar to New Highs.)

Tesla has a growing number of critics who say the stock is overinflated and that the cash-strapped company is struggling to stay liquid. It’s also grappling with production delays. Still, the stock is up about 34 percent in the past year. (See also: Tesla Will Merge with SpaceX: Nomura.)

Last month, Tesla reported fourth-quarter revenue that increased to $3.29 billion, up 44% from a year prior. The company said it is aiming for production of about 2,500 Model 3 vehicles per week by the first quarter of 2018, and 5,000 per week by the second quarter. Its previous goal was to deliver 5,000 vehicles per week by the fourth quarter of 2017, but that target date was moved back due to an issue with battery production.

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