Shares of the electric vehicle manufacturer Tesla fell after the company’s long-awaited robotaxi event, where CEO Elon Musk unveiled the company’s Cybercab self-driving concept car, failed to impress investors.

Tesla shares were down 5.5% in premarket trading at 4:55 a.m. ET on Friday.

Musk unveiled Tesla’s Cybercab concept vehicle on Thursday evening – a low, silver two-seater without steering wheels or pedals. The plan is for the car to be able to drive autonomously when it is launched.

The Tesla boss said the company hopes to produce the Cybercab before 2027, but gave no details on where the cars will be manufactured. He said consumers could buy a Tesla Cybercab for a price under $30,000.

He also said he expects Tesla to introduce “unsupervised FSD” in the company’s Model 3 and Model Y electric vehicles in Texas and California next year. FSD stands for “Full Self-Driving” and is Tesla’s premium driver assistance system, which is now available in a “monitored” version for Tesla electric vehicles.

The technology still requires a human driver at the wheel, ready to steer or brake at any time.

— CNBC’s Lora Kolodny and Michael Bloom contributed to this report