NOTE:The connector/wireless receiver is found inside the back side of the mouse. Trackball comfort: Sculpted shape supports your hand and stays in one place-move the cursor without moving your arm Work and play anywhere: Get smooth, precise cursor control wherever you use your trackball-your desk, couch, even your bed Logitech Unifying receiver: Connect up to six Unifying compatible devices with one tiny wireless.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) receiver that stays in your laptop 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.