The Custom 823 is one of Pilot's flagship fountain pens.
With its unmistakeable unique styling; the elegant and classic translucent amber demonstrator body, with gold trim, smooth 14k gold nib, and high-capacity vacuum filling system. 

This pen doesn't use cartridges, it is fill directly from a bottle.
To fill the pen, unscrew the plunger knob at the end of the barrel and pull back on the plunger. Dip the nib in bottled ink so that the ink is touching the lip of the grip section, then push the plunger down. This will create a vacuum that draws ink into the pen. The ink chamber will fill about 3/4 of the way full—far more ink than a typical cartridge or converter can hold.

Gift box set also includes a 70 ml bottle of Pilot Classic Blue fountain pen ink.