Genius' DX-ECO wireless mouse. This adjustable 800 / 1600 DPI clicker swaps out a recharge battery for a "gold," or electric double-layer capacitor -- you may know it as a super, or ultracapacitor. A step towards a battery-free existence not enough for you? Fine, bask in the knowledge that the DX-ECO also features a carpet, marble and sofa friendly "BlueEye" sensor. Read on for the official PR. Us? We're off to fantasize about battery free electric vehicles.