This is the newest addition to the Logitech Ergo series that promotes increased comfort, lower muscle strain, and improved, more natural posture. Forget about sliding around a mouse or moving your arm to move the cursor. The ergonomic sculpted shape of ERGO M575 minimizes movement and maximizes comfort while keeping your hand and arm relaxed. With two ways to connectvia Bluetooth Low Energy or the USB receiverthe trackball provides you a powerful, stable signal with a 33 ft (10 m) range. No need to move your trackball, so its perfect for tight workspaces and busy desks. A single AA battery lasts up to 24 months with the included Unifying USB receiver and up to 20 months with Bluetooth Low Energy.