Both the Montblanc 420 (production period 1971–1975) and the mechanical pencil 251 (1971–1984) are regular series writing instruments that were offered in this time in the middle to lower price segment. They were only frequently personalised as promotional articles with a company engraving, here 'KAEFER'. Strictly speaking, the two models do not fit together as a set: the fountain pen with gilded steel nib comes from the fourth, very inexpensive series; the pencil with two rings from the second series. Despite the simpler version, they are full-fledged Montblanc writing instruments.