The M575 uses a trackball controller, allowing you to move the cursor with just your thumb and no additional movement from your arm. This reduces fatigue and provides comfort during prolonged periods of use. Additionally, you do not need to move this device at all, making this ideal for compact workspacesLogitech designed the ERGO M575 for long-lasting use, able to withstand more than three million clicks. The advanced optical sensor provides smooth and tactile response, giving you pinpoint accuracy that can be fine tuned up to 2000 dpi. Additionally, you can experience up to 24 months of usage off a single AA battery with ultralow power consumption for prolonged, uninterrupted use.