- Disposable fountain pen. - Ink controller mechanism for no leaks. - Medium tip. - Transparent ink window. - Erasable ink with eradicator. Disposable fountain pen with a large ink reservoir. Priced to compete with traditional liquid ink rollerballs but has a stainless steel fountain pen nib. The medium nib writes a crisp and clean line. No leaks thanks to the ink controller mechanism, which ensures every drop if ink is efficiently used. The barrel has a transparent window for viewing the ink level. Near the end of the barrel is a ink controller mechanism. This ensures that there is a constant ink flow to produce non-skip writing and eliminate blobbing.