1. SLEEK AND RECHARGEABLE DESIGN VERTICAL ERGONOMIC MOUSE : Scientific ergonomic design encourages healthy neutral "handshake" wrist and arm positions for smoother movement and less overall strain 2. MULTIFUNCTION AND CONVENIENT VERTICAL MOUSE 3 ADJUSTABLE DPI : 1000 / 1200 / 1600 DPI Resolution Optical Tracking Technology provides more sensitivity than standard optical mice for smooth and precise tracking on a wide range of surfaces.