M120. Tombow ABT Dual Brush Pen.
August 2022: Full color line recently added!
Comes with two tips of the same color: brush and monoline. The brush tip is fairly large and flexible. A favorite of many lettering artists, these pens are great for blending. The tips self-clean after blending, reducing color contamination. The manufacturer lists these as acid-free, lightfast, and non-waterproof.