Montblanc - MONTBLANC modello "Pix - O - mat", penna a sfera a due colori - MONTBLANC model "Pix - O - mat", two-color ballpoint pen (red and green), 1950s - 1960s, - Catawiki
1970s MONTBLANC PIX-O-MAT CHROMATIC 4 Color Blue Green Black Red Multi-color Brushed Steel Ballpoint Pen