Chinese auto giant BYD has revealed a new smart watch with built-in car keys, which is set to go on sale in April. According to the company, the wearable device will support smart vehicle ignition, smart locking, and the opening of a vehicle’s windows and trunk. In addition, the smart watch will offer step counts, heart rate and sleep monitoring, call reminders and other functions that come as standard on similar devices. The watch features a circular design, with an unlock button in the upper right corner and a lock button in the lower right corner. It comes with a 360 x 360 resolution sapphire screen, medical-grade heart rate sensor, and a 200mAh battery. The battery provides 30 days of stand-by and five to seven days of continuous use, according to BYD. [IThome, in Chinese]