ERGONOMIC SHAPE - Ergonomically shaped design and soft rubber grips conform to your hand to be naturally comfortable and the compact size makes it easy to take with you wherever you use your computer at home, at work or anywhere else, USB receiver is stored inside the mouse where the batteries are located Interface: USB receiver. Mouse Dimensions (height x width x depth)-4.00 x 2.24 x 1.51 inches. Receiver Dimensions (height x width x depth)-0.57 x 0.74 x 0.24 inches CONVENIENT CONTROLS - Easy-to-reach Back/Forward buttons makes moving quickly between documents or browsing your favorite Web sites a breeze MICRO-PRECISE SCROLL WHEEL - With more grooves per millimeter, our new scroll wheel gives you the ultimate navigation experience LONG BATTERY LIFE - 3 year battery life and smart sleep mode help you go longer between battery changes PLUG'N'PLAY CONNECTION - Nano-sized Logitech wireless unifying receiver stays in your computer plug it in, forget it, even add compatible wireless devices without multiple USB receivers