Conklin Mark Twain Crescent Filler Superblack The Conklin Pen Company® was established in Toledo, Ohio USA in 1898. From the Golden era of fountain pens until today, it’s regarded as one of the most significant and innovative American writing instruments manufacturers. Founder Roy Conklin patented the design for the first self-filling pen in 1901. With this patent, Conklin introduced a self-filling mechanism called the Crescent Filler™. The Crescent Filler™ has a piece of metal shaped like a crescent moon, that extends from the side of the pen, and is the key to simple and easy one-hand way to self-fill the pen with ink. The simple depression of the crescent engages the internal pressure bar to collapse the built-in rubber sac. Releasing the crescent allows incoming in k to fill the sac. In 1903 legendary author Mark Twain, the legendary American author, expressed the virtues of this unique self-filling fountain pen. The Crescent Filler™ became one of the most beloved pens in American history. In honor of its continued success, the Conklin Pen Company® is proud to announce the latest addition to the stellar collection: Mark Twain Crescent Filler™ Superblack Limited Edition.