Logitech M570 Wireless Trackball-(Certified Refurbished) Trackball comfort: Sculpted shape supports your hand and stays in one placemove the cursor without moving your arm Work and play anywhere: Get smooth, precise cursor control wherever you use your trackballyour desk, couch, even your bed Logitech Unifying receiver: Connect up to six Unifying compatible devices with one tiny wireless receiver that stays in your laptop 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