TRACKBALL COMFORT - Equipped with a 34mm trackball, you will not need to mouse around to move the cursor as thumb controlled trackball stays in one place. Not only work on flat surfaces, but also on your leg, sofa and other surfaces as well. A full control of everything is within your fingers. | ERGONOMIC DESIGN - Places your hand in a natural wrist & arm position for smoother movement and less muscle tension. Comfortable finger rests just fit in the palm of your hand. No driver required. Once you get used to it, you will love it! | 4 ADJUSTABLE DPI LEVELS - The SANWA trackball provides precise cursor movement for superior accuracy so you can get where you want on the screen quickly with less hand movement, improving productivity and efficiency. You can adjust the mouse among 4 resolutions of 600 / 800 / 1200 / 1600 DPI depending on your needs. When the count switch button is pressed, the DPI is notified by the number of flashes. | PROGRAMMABLE BUTTONS - Download SANWA Trackball mouse software to program mouse buttons. Programming with a single click has never been easier. Work and play more efficiently and quickly.(The software does not work with mac OS or Chrome OS. The software is being upgraded and maintained, and is temporarily unavailable for download and use. We will restore the service as soon as possible. Please understand for any inconvenience caused.) | NOISELESS BUTTON - The noiseless button is mounted on the left and right clicks. Suitable for late-night PC operation, operation in quiet places such as public places, library, hospital or meetings. | RECHARGEABLE WIRELESS MOUSE - Built-in high quality rechargeable battery means you can recharge whenever you want. Do not need to buy a separate dry battery, environmental protection and cost saving.When you leave your mouse more than 5 minutes, it will automatically get into sleep mode which saves electricity of the mouse, and click any button for waking up the mouse again.