about this project ERGONOMIC COMFORT DESIGN FOR HAND AND ARM RELAX: The comfortable, sculpted ergonomic shape fits naturally in your hand. Smooth thumb control, precise tracking: excellent cursor control on any surface. GREAT FOR TIGHT WORKSPACES: Since the trackball doesn't move, it's perfect for tight workspaces and busy desks. 2 WAYS TO CONNECT & MULTI-OS: Simply connect with the Bluetooth or USB receiver within a range of 33ft (10m) without worrying about drops or lag. Nominal: 400 dpi Plastic parts in the ERGO M575 include post-consumer recycled plastic (graphite/black: 50%, off-white: 21%). Responsibly packaged using FSC certified paper. With up to 24 months of use on a single AA battery with the USB receiver, you might forget your trackball is on batteries altogether. Convenient controls: Moving between documents or browsing your favorite websites is a breeze with the large, easy-to-reach back/forward buttons and precise scroll wheel. USB Receiver Height: 0.74", Width: 0.57", Depth: 0.24" Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.