Fisher Non-Pressurized One-For-All Refill - Blue, Medium

These are marvelous refills. The ink is fluid and writes smoothly and evenly every time you put it to paper. They don't leak ink out the end of your pen, they don't gum up or dry out if you don't use them for a week or two, and best of all, they can be sized to fit nearly any pen on this planet. I have some old vintage pens mfd. by Zaner-Bloser, and there is no other refill on the market that will fit through the tip of the pen. These fit like they were made expressly for my pens!!!