Forget about sliding around a mouse or moving your arm to move the cursor. The ergonomic sculpted shape of the M575 minimizes movement and maximizes comfort while keeping your hand and arm relaxed. Scroll wheel with large, easy-to-reach back/forward buttons. Connect with Bluetooth® or USB receiver up to 33 ft. range. 2.4 GHz wireless technology. Medium. Uses 1 "AA" battery (included). Up to 24 months on battery, 20 months with Bluetooth®. 2-year warranty. Graphite.