The Twin Black Marker Assortment Set contains four double-ended markers offering a total of 7 types of tips! These pens all contain the same water based black pigment and are water resistant, smudge proof and lightfast. The Zig Clean Color Dot pen has a 0.5 mm writing tip and a dot tip. The Zig Calligraphy II pen has a 2 mm tip and a 3.5 mm tip. The Zig Scroll & Brush Pen has a scroll tip and a brush tip. The Zig Writer Pen has a 0.5 mm tip and a 1.2 mm tip.