This the world's first retractable fountain pen, by Pilot, Japan. It has a full size metal body and a 18 karat pure gold nib. Its nib is opened and closed like a ball point pen by pressing the large button that opens a small trap door that seals the nib and ink. One of my favorite. It was originally launched in Japan in the 1960s' and went through several generations of refinements in 50+ years. The nibs can be replaced in 15 seconds and are available in FINE, MEDIUM and BROAD.