Additional Details ------------------------------ Bullet point: Polyacetal resin tip for Super fine strokes Metal reinforced collar nib is suitable for ruler and template work without causing any nib damage Friction-proof nib enables to draw a consistent writing width Acid free Excellent water-durable and fade-proof Real black and pure red due to Super-fine grained and water-based pigment ink. Product description: Polyacetal resin tip for Super fine strokes Metal reinforced collar nib is suitable for ruler and template work without causing any nib damage Friction-proof nib enables to draw a consistent writing width Acid free Excellent water-durable and fade-proof Real black and pure red due to Super-fine grained and water-based pigment ink.