akgideon,<br><br>If the pen you're referring to is this one...<br><br><br>...then it may be half the size of a full sized Fisher pen, but it looks like it would be just about the same as the Fisher Bullet pen.<br><br><br><br><br><br><br><br>Of course, comparing images I snagged off the web can be misleading. My bullet pen is about 3 5/8" long. How long is the Zero Gravity Pen?<br><br>In either case, it would take up less room in a PSK if you just bought and carried the ink cartridge, and forgot about the pen body.