Pilot Acroball Knock Ballpoint Pen, 0.5mm Extra Fine, Black(BAB-15EF-BB), 6 pens per Pack (Japan Import) [Komainu-Dou Original Package] Go to amazon.com Related posts Top 10 pilot 0.5mm pen FeatureSmooth ink oil-based ballpoint penKnock type DescriptionSmooth ink oil-based ballpoint pen. Knock type.