USB extension cables are used to extend the connection to a large number of devices, such as computer keyboards, printers, mice, and SD card readers. Extension cables for USB typically come with A connectors on both sides, one male and one female. This allows standard USB devices to attach on the female end. A USB type A cable used by most devices will plug into the female end of the extension cable; the cable will then plug into the computer. USB can be extended up to 9.5 to 16 feet passively; for longer reach you can add an USB active extender for up to 80 feet on most devices.</p>