Model 400, the successor of model 100N, was introduced on May 25, 1950. Like 100N, model 400 had the differential piston filling mechanism. In other respects, changes were made throughout. The redesigned feed had four lamellas and more complicated ink and air channels. The socket was a traditional screw-in fit but equipped with two notches to apply the special wrench. The clip resembled more closely the face and beak of a pelican than that of model 100N did, and the cap tube had a single wide brass ring. The barrel had alternating colored and transparent stripes, through which ink was visible. The diameter was almost same as that of model 1ooN, but the over all length was about 5 mm longer. The filling mechanism was fixed with the barrel in a friction fit manner. The model was made in several colors, but the most common was by far the combination of green stripe and black cap, echoing the traditional color scheme that distinguished Pelikan fountain pens at least as much as its logo. Model 400, with its new clip and the vertical stripes of the body became one of the symbols of the postwar modernist style, achieving enormous success.