Translations:Button filler/4/en

Pressing the button causes the rod to bend towards the center of the pen, causing the sac compression. Again, a pressure bar is used to make the sac more evenly compressed. The advantage of this system is that there is no need for a side slit in the pen body. The fact that the access to the button was protected by an screw-on blind cap allowed to affirm a greater security than the loss of ink in case of breakage of the bag, also the system was promoted for its ability to allow the loading of the pen with one hand.