Leuchtturm1917 Drehgriffel Nr. 1 Ballpoint Pen refills are document-proof and water-insoluble.

The available line widths are Flow F (fine), Flow M (medium), and Flow B (Bold) in blue and black. The package includes 2 refills, and it is suitable for use with most other pens with Parker-style refills.

Stainless-steel tip with tungsten-carbide ball.