This is a Montblanc 220 cartridge / converter fountain pen in black c. 1971-1977. The 5 5/16 inch long pen also came in a piston-fill version, and both have narrow ink view windows where the barrel meets the section. In the cartridge pen, the section threads are clear, extending up to the ink view window, which can only be seen with the cap off. The 220 has a single cap lip band and can be distinguished visually from the 221 as that pen has two bands. The Montblanc logo is on the cap top and barrel end and MONTBLANC and GERMANY are stamped on the cap band. It has a 14 karat gold nib stamped 585, though some versions have 18 karat gold nibs stamped 750. It came in matte black resin and polished resin in black or burgundy. Gold and silver color trim versions, with matching color nibs, were made, and some pens have matte trim. Some pens will have cap tops with black surrounds instead of gold plated, as on this example.