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 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) 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