Combines the feel of a wireless mouse with the precision of a trackball. Ergonomic design with a 45° tilt helps improve wrist and forearm alignment, takes up less desk space, and is more comfortable during extended use. Features long battery life, patented ball ejection system for easy cleaning, and precision optical-tracking technology. Dual wireless Bluetooth® Low Energy (LE) and 2.4GHz connection capability. 1 "AA" battery (included). 3-year limited warranty. Medium. Black.