Translations:Sleeve filler/3/en

The presence of the sleeve that wraps around the barrel at the opening, however, makes the size of the body of the pen uneven, which are therefore often unpleasant from an aesthetic point of view. Moreover, the mechanical complexity of the pen and its general fragility are greatly increased, since the pens of that period were made from hard rubber, a material not particularly resistant to mechanical stress. For this reason this filling system had a reduced diffusion and was soon abandoned.