Laptop Docking Stations: The Mac OS itself does not support extended screen effect. MCY 12 in 1 usb c triple docking station achieves the extended mode by the following steps needed from you: Settings-Display-Arrangement-Cancel Mirror Display. Also please drag the setting box to the page of the external screen. Then you can get one display of HDMI1+HDMI2+DP, one display of your laptop. Totally two different contents for Mac OS 12 in 1 Docking Station: Perfectly combined the function of USB C Hub and docking station featuring type c port (85W PD charging), 24K HDMI ports,14K DP port, 2*super speed USB 3.0 Ports(Up to 5Gbps), 2 standard USB 2.0 Ports, Ethernet RJ-45 port, SD/TF card reader, USB3.1 Type-C; Make Your Life More Intelligent; Specially designed for usb interface equipment Docking Station triple display: MCY Type C Hub expand triple monitors with our Adapter, HDMI port support up to 4K@30Hz; DP port support up to 4K@30Hz. When using Triple display mode, For Mirror mode 3