Size: Length - 104mm capped; 132mm inches posted; 13mm max. diameter.
The Moonman No. 80 is an homage to the very popular and long-lived Parker 45 pen. It shares its profile and distinctive nib. The No. 80 Mini adds a twist - the pen is a re-imagining of an oriental Short Pen or pocket pen. It has a really diminuitive size when capped, but if you remove the cap and post it, the pen becomes long enough to use for extended periods of writing. This pen is a cartridge pen only due to its very short barrel and has an iridium-tipped stainless steel nib in a fine point.
Moonman use the Parker style 3mm cartridge peg, so the cartridges you need are the Moonman brand (see below), or the Parker mini cartridges.