A new standard of comfort and precision. Logitech most advanced trackball for trackball enthusiasts and and consumers searching for alternatives to mice and touchpads. Delivers 20% less muscular strain compared to a regular mouse. A unique adjustable hinge offers personalized comfort - Choose the best angle for you between 0 and 20°. precision mode button allows to instantly switch between speed and precise tracking.easy-switch and flow-enabled for effortless multi-computer workflow. Pair up to 2 computers and easily switch between them, copy and paste text, images and files. 1 long-lasting and fast rechargeable battery: up to 4 months on a full charge and ONE minute of charge gives up to one full day of use.2 Connect using the included Logitech Unifying receiver or via Bluetooth.1 requires Logitech options software, available for download at Logitech.Com/options. 2 Battery life may vary based on user and computing conditions. MX ERGO Height x Width x Depth: 5.22 in (132.5 mm) x 3.93in (99.8 mm) x 2.02in (51.4 mm) Weight: 5.78 oz (164 g) (without metal plate/without receiver) Weight: 9.14 oz (259 g) (with metal plate/without receiver) Unifying Receiver Height x Width x Depth: 0.72 in (18.4 mm mm) x 0.57 in (14.4 mm) x 0.24 in (6.1 mm) Weight: 0.07 oz (2 g)