Pitt Artist Pen Pen Set 4 Black (f, S, M, B) | Faber-Castell

pigmented india ink, high light fastness, waterproof, permanent, odourless, acid-free, neutral ph. case with 4 stroke widths: s = 0.3 mm, f = 0.5 mm, m = 0.7 mm, b = brush tip. ideal for sketching and oversee the drawings to china.