Fisher Space Pen Tough Touch, Black (S-TT/B) Conductive Stylus is ideal for touch screen cellular smart phones and tablets. Type faster with greater accuracy, reduce smudges, scratches and oil marks. Replaceable tip. Writes Underwater, Upside Down & At Any Angle, Over Grease, 3X Longer Than an average Pen. Also writes in Extreme Temperatures (-30 Degree to 205 Degree). Each Fisher Space Pen is precision assembled, hand tested, and carries a lifetime guarantee against all manufacturing defects Aluminum and Brass construction