Contain extremely fine polyacetal plastic nibs set in 0, 5mm Stainless Steel sleeve for smudge-free inking, Ideal for precision drafting free-hand drawing or any design work, Water-based pigment ink is non bleeding waterproof and fade proof, The acid-free archival quality ink is also quick drying and lightfast, These disposable technical pens are offered in five line widths, Sets are supplied in protective vinyl sheath, SKU: ALV1855