Pilot refill acroball pen, black, fine, 2/PK detail ink provides smooth, waterproof, and quick-drying performance. Specially designed acroball PureWhite, acroball color and acroball Pro pen are used. Pen Refill Type: Ballpoint Pen; Refill Series: Pilot acroball Point Type: Fine Ink Color S Black Write; Musical Instrument; Ink; Tube; Reservoir; Pen Ballpoint Pen Refill