Support bus-powered (without power adapter) - Supplemental Power Solution for a Stable Connection. Plug & Play, no Installation and Hot Swappable. Increase the Productivity of Your Laptop - Easily connect with any devices of cellphone, card reader, hard drive, keyboard, mouse, printer, etc. Expand your laptop with more USB-A ports, don't limit it. Energy Saving at Your Fingertips - Respective indicators for each port can easily show the working status. Turn off the idle port for power saving. Individual On/Off Switch - With an individual switch for each port, easier to turn on/off the USB port instead of plugging/unplugging. Organize your USB Peripherals in a easier way. Access Memory Instantly - Convinient SD & micro-SD Card reader, easily reach your photos or videos from SD/micro-SD card, perfect for Photographer or designer, etc.