[Super Speed Transmission]: Built-in USB 3.1 chip, the transmission speed can reach 312MB/S. Type-C interface supports plug-and-play, compatible with Type-C smartphones& tablets [SD Card Reader& Holder 2in 1]: This multi-functional memory card storage case integrates memory card storage and ultra-high-speed data reading functions. As a card case, it can accommodate 2 Nano SIM cards, 4 SD cards, 4 TF cards, and an eject pin. As a card reader, SD and TF dual card slots support data transfer all at once [Broad Compatibility]: Widely supports different kinds of memory cards, such as UHS-, SD 4.0: UHS-SDXC/SDHC/SD cards, UHS-SDXC/SDHC/SD cards, UHS- micro SDXC/micro SDHC/micro SD cards, UHS- micro SDXC/micro SDHC/micro SD cards, compatible with Windows 7 and above, Mac OS 10 and above, Linux, Android, iPad OS [Metal Jacket& Rubber Case Protection] Aluminum-alloy material shell& rubber case which can reach IP54 waterproof level to protect your sd cards. Packing list: carNote: Data transfer only applies to Type-C port phones and tablets that support OTG; To connect with a desktop computer, a Type-C to USB-A adapter is requiredd reader case *1, rubber case *1, carabiner *1 , eject pin *1, user guide *1, logo sticker *1 Note: The ideal transmission speed will be 312MB/S if your cards are SD 4.0; the speed will also be influenced by internet environment and device performance