Fisher Space Pen Tough Touch Space Pen (TT) 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 F to 205 Degree F). Each Fisher Space Pen is precision assembled, hand tested, and carries an unconditional lifetime guarantee. Aluminum and Brass construction