The Diamond 580 comes with a benchmark piston ink-filling mechanism. It’s clear and comes with all detachable parts. The pen is very nicely made. It feels solid and of high quality. The nib is smooth with a little feedback.

TWSBI Diamond 580, a classic fountain pen with a piston ink-filling system. By fusing the traditional mechanisms of the fountain pen with a modern industrial design, we have created an eye-catching fountain pen that is simultaneously appreciative of the past and relevant in the present. The Diamond 580 comes with a benchmark ink-filling mechanism and has all detachable parts. We felt that it was important to allow the user to disassemble and reassemble the pen and completely experience the traditional aspects of owning and using a fountain pen.

• Body Material: Resin
• Cap Type: Screw-cap
• Compatible inks & refills: Bottled inks
• Filling Mechanism: Piston
• Nib Material: Steel
• Diameter: 0.5″
• Length: 5.1″
• Max Ink Capacity: 1.98ml
• Release Date: 4/22/2022
• TWSBI Diamond Ink Bottle

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About TWSBI:

TWSBI (San Wen Tong) is one of our earliest collection even before the store. TWSBI started as an OEM manufacturer for different western brands, and around 2009, they decided to start their own brand. With 50 years of experience in pen making, they took to fountain pen forums and gather users feedback. It was said that Pelican M800 was the model they were inspired. Most of their pens are transparent, so its really fun to see the ink color and it lasts for a very long time.

The name (San Wen Tong) comes from the Hall of the Three Rare Treasures, created by Emperor Qianlong as a memorial to three great masterpieces of Chinese calligraphy. The initials of the name San Wen Tong was reversed and thus turned into “TWS”. The last letters “Bi” was added with its literal meaning of “writing instruments” in Chinese. Thus combining the two segments, creating TWSBI.