Forget about sliding around a mouse or moving your arm to move the cursor. The ergonomic sculpted shape 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.