USB-C to Dual HDMI Adapter 2 in 1: ❤️Attention: On Mac devices, ONLY Mirror Mode, CAN NOT extend two different Screen, due to Mac OS limitation Connect device with USB Type C (tunderbolt 3) port to two external monitors with 4K HDMI output You can enjoy movies,games with your families on external ultra HD big screen Windows OS supports both SST and MST mode, if you not sure how to setting, please contact us, or download the user guide in Product information->Product information.