Hertz CEO Mark Fields said that the company’s agreement to deliver Tesla vehicles to Uber includes an option for an additional 100,000 Tesla Model 3 sedans, which could bring its total order to 200,000 vehicles.

Hertz revealed earlier this week that it has secured the purchase of 100,000 Tesla Model 3 vehicles as part of a new initiative to electrify its fleet.

It was revealed Wednesday that Hertz would only be using half of the 100,000 cars it has purchased in its fleet of automobiles accessible for hire to ordinary customers at airports and other locations

Meanwhile, the other half of the Tesla sedans will be made accessible to Uber drivers as part of Hertz’s separate deal with the ride-hailing company.

Fields confirmed the arrangement, stating that the deal may call for the purchase of a total of 150,000 vehicles instead of 100,000. Uber drivers will be able to rent the Tesla Model 3 sedans owned by Hertz for $300 a week.

Uber CEO Dara Khosrowshahi said she is confident that drivers will grab the deal based on their data and research. She said if the program will be successful, Uber and Hertz could grow their electric fleet to 150,000 vehicles.

Currently, the arrangement covers 50,000 Model 3s from Hertz’s purchase of 100,000 Model 3 vehicles, which Tesla is expected to deliver by the end of next year.

If Hertz plans to use the other half of their initial order to update the main rental fleet, increasing the deal with Uber to 150,000 vehicles over the next three years will necessitate ordering the additional electric vehicles from Tesla.

Fields denied that Hertz has received a discount with the bulk order. Typically, companies that order a large fleet do receive a discount. Fields declined to comment on the total cost of the purchase. Tesla CEO Elon Musk also previously said that the contract with Hertz did not include a discount.