China’s leading train manufacturer has unveiled a prototype maglev train that will eventually carry passengers at speeds of up to 373 mph (600 km/h). CNN reports that the train, developed by the state-owned China Railway Rolling Stock Corporation (CRRC), will now enter a period of testing, before full production is expected to begin in 2021.

373 mph is fast, so fast that it could allow the train to transport passengers between Beijing and Shanghai in just three and a half hours, compared to the four and a half hours it currently takes a plane to make the journey, according to CRRC’s deputy chief engineer Ding Sansan. That’s in spite of the fact that the typical cruising speed of an aircraft is between 547 and 575 mph (880 and 926 km/h).

Japan holds the current world record for maglev train speeds

The train will be able to reach these theoretical speeds thanks to its maglev design, which sees it travel on a magnetically powered cushion of air rather than using wheels that are in constant contact with a track. China already has the world’s fastest commercial maglev service in operation, which reaches 267mph (431 km/h) on its 18.6 mile (30km) journey between Shanghai’s airport and city center.

CRRC’s prototype, which was first announced back in 2015, won’t be the first train to hit these kinds of speeds. Back in 2015, Japan set a new world speed record with a maglev train of its own that hit 375 mph (603 km/h). The country is currently building a 314 mph (505 km/h) maglev rail line between Tokyo and Nagoya that’s due to open in 2027.