Those Misfit fitness trackers — like the Shine — are big in China.

“We’re the No. 1 activity tracker in China right now,” Misfit CEO Sonny Vu told VentureBeat Monday.

And by the sound of things, Misfit is going to get even more popular in China with the help of some big friends.

The company raised a new $40 million in venture funding from a group of investors including Chinese tech giant Xiaomi (the world’s third largest smartphone maker), Misfit is announcing today.

“We have known Xiaomi for a long time and really like what they do,” Vu said. The investment marks Xiaomi’s first in a U.S. company.

New investor GGV Capital led the round. JD.com, Shunwei, and existing investors Founders Fund, Khosla Ventures, Horizons Ventures, and Norwest Venture Partners also participated.

JD.com is the largest direct-to-consumer ecommerce company in China. “It’s like having Amazon invest in you,” Vu said.

Vu said his company raised the new round for two main reasons. “The whole point of doing this, since we didn’t really need the money, is to scale up for accelerated product development,” Vu said. “The second reason is to really extend our ability to address the needs of the Chinese consumer.”

Misfit raised $15 million last year but hasn’t had to use much of that money to date. Vu said his company has sold enough product to hit break-even.

GGV Capital managing partner Hans Tung was an early investor in Xiaomi and now takes a seat on Misfit’s board of directors.

Hans Tung, Managing Partner of GGV Capital and an early investor in Xiaomi, will be joining the Misfit Board of Directors. Tuck Koh, founding partner of Shunwei, will be becomes a Misfit board observer.

Misfit’s last major product release was the $50 Misfit Flash fitness tracker, a less expensive version of its flagship Shine.