Quick User Guide
1) The USB C to HDMI VGA adapter only work for USB C(USB 3.1) and thunderbolt 3 devices that support DP Alt mode. Please check the equipment manual before purchase.
2) In order to enjoy the 4K high resolution, please make sure to use a 1.4 or higher version HDMI cable, and 3+9 VGA cable.
3) When two ports work simultaneously, the image on the two external monitors will be the SAME. The Extend mode only work for laptop. 4) Mirror and Extend Mode Settings:
For Windows 10: Press Windows key + P combination command-->choose Duplicate or Extend.
For MacOS: Apple Menu-->System Preferences-->Displays-->Mirror or Extend Displays.
5) If the resolution of your laptop is higher than the external monitor,please set your laptop's resolution same as or lower the resolution of external monitor.
For Windows: Windows Menu--> Setting--> Display--> Advanced Display Settings.
For MacOS: Left-upper Apple icon-->System Preferences-->Displays-->Mirror displays, choose "Optimize For" your built-in Retina Display or your HDMI monitor.
6) If it does not work, you can go to the official website of your laptop, update the BIOS and graphics driver, and try again.

Compatible Devices (Not a full list):
Laptops
1) MacBook Pro(2015/2016/2017/2018/2019/2020)
2) MacBook Air(2018/2019/2020)
3) Apple iMac
4) Chromebook, Chromebook Pixel
5) Microsoft Surface Book 2/Surface Go
6) HUAWEI MateBook 14/13
7) Dell XPS 12/13/15, HP Envy 13, Galaxy Book
8) Surface Book 2, Surface go

Tablet & Smart Phone
1) iPad pro/Air 2020
2) Samsung Galaxy S8/S9/Note 8/Note 9
3) Huawei MATE10/MATE10 PRO/P20/P20PRO
4) LG G5 HTC: ULTRA, M10
5) Microsoft: 950,950X

Systems
Chrome OS; Windows7 / 8/10; Mac OS; iPad OS; Linux; Vista