The best way to keep your knives as sharp as possible is to sharpen them regularly, but as anyone who has ever attempted to do so can tell you, traditional sharpening stones can be a huge pain to use.
And even worse, the duller your knife gets, the harder it is to get it sharp again.
Electric sharpeners, on the other hand, are easier to use and make short work of even the dullest blades. (Even your dullest, the most beat-up knife will be razor-sharp in less than a minute.)
USB current: 5V 2A
Size: 23.5 x 9 x 6.5