The usb3c hub2cr wpd is a usb c to two port usb 30 hub with usb c charging port and micro sd and sdmmc port the usb 30 port allows you to connect a usb device or another hub to the host usb c computer the usb c female port can charge the host computer the micro sd and sdmmc port allows you to access memory cards on the host pc it can work on macbooks or googles chromebook pixel as well as other usb c supported devices note the micro sd and sdmmc port wont work simultaneousl