Zhao Jianbo's factories, also in Guiyang, make manhole cover. [Photo by Yang Jun/China Daily]

What Zhao Jianbo, 46, does for a living isn't anybody's guess. He makes manhole covers that hide sewers and the general underground.

In the late 1990s, Zhao, who was then a migrant from East China's Zhejiang province, used to plant saplings near an arterial road in Guiyang. At the time, he says, the manhole covers in use either made much noise when cars went over them or the metallic ones were frequently stolen. Such thefts happen in many countries.

The son of farmers from the port city of Ningbo, Zhao spent five years as a planter in Guiyang, where he collected 1,000 yuan, which was a large sum back then but not enough for his dreams. And while he often thought about the manhole covers, there wasn't much he could do until friends pitched in to help him start the business in 2003.

His two factories, one in suburban Guiyang and another inside the city, manufacture manhole covers in composite and desiccant materials that are lighter in weight than the traditional ones made of concrete or cast iron. They come in three standard sizes of up to 950 millimeters. The units of 300 employees make roadside flowerpot holders as well.

His Guicheng Group produces 1 million covers each year, selling them in Guizhou and the neighboring provinces of Sichuan and Yunnan, and in southern Guangxi.

The group's income from sales is between 200 million and 300 million yuan.

Dressed in blue jeans and a deep pink T-shirt, and standing amid piles of manhole cover at one of his plants with a floor space of 30,000 square meters, Zhao poses for the camera before leading the way to his office inside the compound. For him, research in materials that are safer with regard to accidents is vital in his line of work.

"I plan to get on the Belt and Road Initiative," he says of the central government's transnational economic vision.