A NEW STANDARD OF COMFORT AND PRECISIONLogitech's most advanced trackball for trackball enthusiasts and consumers searching for alternatives to mice and touchpads. Delivers 20% less muscular strain compared to a regular mouse. MX ERGO features a unique adjustable hinge for personalized comfort and the latest tracking scrolling and power management technology. Logitech FLOW enables effortless cross computer control.CUSTOMIZED COMFORTFinally a trackball you can truly call your own. A unique adjustable hinge allows you to choose the best angle between 0and 20 for a more natural hand position and greater comfort.ADVANCED TRACKING AND PRECISION MODE BUTTONChange the speed and accuracy of your cursor for optimal control with a press of a button.PRECISION SCROLL WHEEL WITH TILTGet things done faster with quick access to shortcuts. The precision scroll wheel features horizontal scrolling and a convenient middle click.EFFORTLESS MULTI-COMPUTER WORKFLOWConnect and work on two devices at the same time and easily switch between them. Boost your cross-computer experience with Logitech FLOW technology. Copy and paste text images and files between computers. LONG-LASTING AND FAST RECHARGEABLE BATTERYBattery holds power for up to 4 months on a full charge. One minute of charge gives up to a full day of use