Translations:Button filler/3/en

In this case, the system requires that the compression of the rubber sac is carried out through a flexible metal strip (often called "I-bar") that is curved by pressing it with a button on the bottom of the pen. The strip in the rest position is straight and resting on one side of the pen body. On the underside it is placed in contrast with the nib assembly (in some cases a special recess is created on the body itself). On the upper side it comes out, through a curved end, from a hole made on the bottom of the pen, and inserted into a metal button.