Trackball comfort: Sculpted shape supports your hand and stays in one place move the cursor without moving your arm * Logitech Unifying receiver: Connect up to six compatible wireless devices with one tiny receiver that stays in your laptop * Long battery life: Go for up to 18 months without changing the included AA battery * Smooth cursor control anywhere: Precision laser tracking on your desk, couch, bed or almost any other surface * For Windows or Mac OS: Control your laptop, desktop computer or home theater PC wirelessly from up to 30 ft. away