Tp-link uh400 is a 4 ports usb 3.0 Hub, no power adapter needed. It can transform one of your computer's usb ports into four. With foldable cord, lightweight and portable design makes it a great travel companion to expand your laptop's usb 3.0 Port into four. Fully backwards compatible with the usb 2.0/1.1 Products. With tp-link uh400, you can now transfer data at up to 10 times the speeds of the older usb 2.0 Standards. Speeds of 5gbps are a vast improvement over usb 2.0'S 480mbps top speed. It is also backwards compatible, allowing you the capability of using usb 2.0/1.1 Products if need be. Please note: 2.4Ghz wireless devices, such as wireless keyboard and mouse adapters, may not work in close proximity to usb 3.0 Devices or hubs. Connecting to a usb 2.0 Port is recommended. For a stable connection, don't use this hub with high power-consumption devices (the devices connected to the 4-port usb 3.0 Hub must not exceed a combined current of 5 volts 900 mah), such as external hard drives, tablets and other devices which require a higher power input.