The USB3C-HUB3CR is a USB-C to three USB 3.0 hub with a Micro SD and SD/MMC port. The USB 3.0 port allows you to connect a USB device or another hub to the host USB-C computer the Micro SD and SD/MMC port allows you to access memory cards on the host PC. It can work with Macbook s or Google s Chromebook Pixel as well as other USB-C supported devices. Note: The Micro SD and SD/MMC port will not work simultaneously you can choose to use one of them according to your practical need. Supports USB-C Male 3x USB 3.0 Female SD /MMC card Micro SD card interface Supports to connect 3 USB 3.0 supported devices simultaneously The max total output of the 3 USB outputs is 900mAh Support USB 3.0 Super Speed (5Gbps) transmission backwards compatible with USB2.0 Supports USB-C input USB 3.0 output USB 3.0 port supports to charge and transmit data for the USB device simultaneously Supports SD/SDHC/SDXC Supports Secure Digital v3.0 UHS-I (Reading speed max 70Mbps Writing speed max 90Mbps) Supports MultiMediaCard (MMC) specification Supports Micro SD/SDHC/SDXC (up to 128 GB).