Logitech'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.= Logitech FLOW™ enables effortless cross computer control. Key Features: CUSTOMIZED COMFORT Finally a trackball you can truly call your own. A unique adjustable hinge allows you to choose the best angle between 0°and 20° for a more natural hand position and greater comfort. ADVANCED TRACKING AND PRECISION MODE BUTTON Change the speed and accuracy of your cursor for optimal control with a press of a button. EFFORTLESS MULTI-COMPUTER WORKFLOW Connect 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.* Package Contents: - MX ERGO Mouse +That is all that is included.