TWSBI Diamond 580 AL Emerald Green
TWSBI Diamond 580 AL Emerald Green has exactly the same dimensions as the 580 version but differs in some details that are presented in aluminum and green color.  
Like the previous model, it stands out for its excellent value for money and a wide choice of nibs.
It is also one of the cheapest pens on the market to have piston loading.

One of the features most appreciated by enthusiasts and not, is the ability to disassemble piece by piece the entire structure of the TWSBI Diamond 580 Al-Green. This operation, which greatly facilitates the cleaning and therefore the longevity of the pen, is possible thanks to the tools that are supplied inside the package and together with the pen.
It should also be noted that for the TWSBI Diamond 580 the Extra Fine, Fine, Medium, Large nibs are available.