-Notes 1.

Some refills are printed on the tube so that the refill color and ball diameter are easy to understand when set to the Style Fit holder.
This refill has a window to check the remaining amount of ink, and when the ink runs out, it looks like "Air has entered from the tip of the pen".

-Notes 2.

There are types of refills that can be seen in shape and color, as if air has entered from the pen tip.
The red frame on the left is in a normal state. If you cannot write with such an appearance, there are other causes.

c) In case air enters from the pen point

As in the illustration above, when writing with the tip of the pen pointing horizontally or higher, air enters from the pen tip ink cannot transmitted to the pen tip like the photo below.

• The ballpoint pen ink flows to the pen tip with the weight of the ink itself (gravity). For this reason, if writing with the pen point not pointing downwards, air enters in the pen, and the pen tip and ink are separated from each other, making it impossible to write.
• In order to let the air entering the ink out from the pen tip, it is necessary to apply a pressure that is strong enough to eject the ink from the back of the pen to the pen tip. Therefore, it is extremely difficult to restore.

＊Pressurized Ball-Point Pen “POWER TANK” applies pressure to the ink so that the pen tip does not get in the air even if writing upward.