Trackball comfort: Sculpted shape supports your hand and stays in one place-move the cursor without moving your arm</br>Work and play anywhere: Get smooth?? precise cursor control wherever you use your trackball-your desk?? couch?? even your bed</br>Logitech Unifying receiver: Connect up to six Unifying compatible devices with one tiny wireless receiver that stays in your laptop</br>Long battery life: Go for up to 18 months without changing the included AA battery* (*Battery life may vary based on user and computing conditions)</br>For Windows or Mac OS: Robust 2.4 GHz wireless connection lets you control your laptop?? desktop computer or home theater PC wirelessly from up to 30 ft. away** (** Actual wireless range will vary with use?? settings and environmental conditions) Please refer the User Manual before use.<