The Coleto Lumio is a pen.
Actually, it's just the shell of a pen — you get to choose four ink refils to put in it.
I am an avowed fan of the Hi-Tec-C pens from Japan because of their amazingly fine line and quick-drying ink, which are great qualities to have when marking up page proofs and taking notes during pub quiz.
I was looking online for refills, since my green one is running low, and found that I can get this shell and some refills and make my own four-color pen. Squee! I placed my order yesterday.