The TWSBI Diamond 50 Fountain Pen Ink Bottle combines elegance and practicality in a 50ml glass bottle. Its premium anodized aluminium cap and innovative dual-chamber design make refilling your fountain pen effortless. The clever upper reservoir fills automatically when the bottle is inverted, making it simple to draw ink even as levels run low. Ideal for all fountain pens, it’s particularly convenient for TWSBI Diamond series pens (530, 540, 580, and Mini) thanks to the included filling adapter, allowing direct barrel refills without submerging the nib. Clean, efficient, and stylish, the Diamond 50 keeps your writing flowing smoothly.

Product features:

• Made in Taiwan.
• 50ml premium glass ink bottle with anodized aluminium cap.
• Innovative dual-chamber design simplifies refilling.
• Upper reservoir allows easy ink drawing when bottle is low.
• Compatible with all fountain pens; includes TWSBI adapter for direct barrel refills.
• Clean, efficient refilling without messy nib dipping.
• Ideal for TWSBI Diamond series pens (530, 540, 580, Mini).

View our range of TWSBI products.