The Logitech Marble Mouse USB T-BC21 Trackman Trackball 810-000767 is a versatile trackball mouse with a sleek gray design. Featuring a maximum DPI of 300 and programmable buttons, this ergonomic mouse offers precise control for a comfortable user experience. With USB connectivity and a trackball tracking method, this mouse is a reliable choice for those looking for a unique and efficient pointing device. Its 4 buttons and ergonomic design make it a convenient option for users who prefer a trackball mouse for their computing needs.