Rapidograph pens are reknowned for providing precise line widths in technical and detail drawings. Hard chrome, stainless steel points are long-wearing. White plastic barrel is fillable ink reservoir, they do not come pre-filled. Air-tight double-seal keeps the point from drying out. Packaged in a hinged-lid case with a 3/4 oz. bottle of Koh-I-Noor Ultradraw clog-resistant black ink and twi nib keys.  Contains pen sizes: 3x0(0.25mm), 00(0.30mm), 0(0.35mm), 1(0.50mm), 2(0.60mm), 3(0.80mm) and 4(1.20mm).  AP Seal, non-toxic.