<ul><li>3 button design</li><li>Rubber scroll wheel</li><li>Nano receiver is hidden in the Mouse button</li><li>2.4 GHZ wireless technologyOptical Technology</li><li>Built-in energy saving system</li><li>Elegant and Ergonomic DesignScroll easily in any direction</li><li>Two-way transmissionAutomatic frequency-hoppingAnti-jamming capability.</li><li>Doesn't contain power on/off button.</li><li>Only plug in and use it.</li></ul>