ULTRA-QUIET MOUSE - 90% reduced click sound and same click feel eliminates noise and distractions for you and others around you QUIET MARK CERTIFICATION - Logitech is the first mouse company in the world to receive the Quiet Mark certification from the UK Noise Abatement Society that internationally recognizes technology designed to reduce noise ERGONOMIC SHAPE - Designed with contoured grips made of soft rubber for total comfort LONG BATTERY LIFE - 2 year battery life and auto-sleep 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. Note: No Bluetooth connection, only USB connection