A better mix of precision and comfort-with designed-for-Web scrolling. Designed for how you use the Web, our newest micro-precise scrolling makes everything you love to do online easier. Its feel-good, contoured shape and textured grips help keep your hand happy-even after long hours. And with up to 18 months of battery life, it virtually eliminates the hassle of changing batteries. Designed to improve your online experience, the wheel also helps perfect scrolling when you're using other applications, such as Microsoft Office or Adobe PDF. Battery life may vary based on user and computing conditions.