<noinclude>{{ReferBox|Filling systems}}</noinclude>It was introduced by [[Parker]] in [[1948]], as a new filling system adopted on the [[51]] in place of the previous ''[[vacumatic filler|vacumatic]]''. Actually for the operating modes this system is very similar to the ''[[sleeve filler]]'' used by [[LeBoeuf]], because it is based on the pressure of a rubber sac to be made by a side opening on the metal cylinder that contains the same, which is accessed by unscrewing the pen body from the nib section. | <noinclude>{{ReferBox|Filling systems}}</noinclude>It was introduced by [[Parker]] in [[1948]], as a new filling system adopted on the [[51]] in place of the previous ''[[vacumatic filler|vacumatic]]''. Actually for the operating modes this system is very similar to the ''[[sleeve filler]]'' used by [[LeBoeuf]], because it is based on the pressure of a rubber sac to be made by a side opening on the metal cylinder that contains the same, which is accessed by unscrewing the pen body from the nib section. |