Onten USB C to dual HDMI & VGA triple monitors display.single HDMI 4K@60HZ , dual hdmi 4K@30HZ, If connected to VGA interface, the resolution will be 1080P. USB C Dock station for windows and mac os .For Windows, it can be mirrored and expanded, and two different screens can be expanded.For Mac OS, it can also be mirrored and expanded, but the two expanded screens are the same

Mirror and Extend Modes
It supports mirror mode on both Windows and macOS computers.
It supports dual extend mode A-B-C-C (MST) on Windows PC to display different images on two external monitors.
It supports single extend mode A-B-B (not MST) on macOS to duplicate the same image on two external monitors.

How to set up multiple screens on Windows?
STEP 1: select Start > Settings > System > Display. Your PC should automatically detect your monitors and show your desktop. If you don't see the monitors, select Detect.
STEP 2: in the Multiple displays section, select an option from the list to determine how your desktop will display across your screens.
STEP 3: once you've selected what you see on your displays, select Keep changes.
STEP 4: you can change the resolution of your displays. However, we suggest using the recommended resolution to get the most out of your displays.