Besides the great gel ink pens, Muji also stocks a nice aluminum fountain pen called, approriately, the Alumi-Round Fountain Pen. The Alumi-Round is a slim fountain pen with an iridium fine point nib. The pen is a matte silver color with a honeycomb grip that doesn't irritate the finger, even though it's a bit rough. It measures about 5 1/8 inches capped; 6 1/4 inches posted; and about 5 inches open, about a standard length yet the pen seems longer and sleeker. It takes international cartridges, such as the Mont Blanc black ink cartridge I am currently using but will probably also take a converter. I haven't checked to see what kind of converter it will take, as I'm content with the cartridge system right now.
The pen writes smoothly, with just a slight resistance to the Whitelines paper I used. It's a wet nib, with lots of ink flow, but there's no feathering and the line width is quite nice although it seems just a touch broader than some of my other fine point nibs. All in all, for $15.50 this is a very good fountain pen with a sleek, contemporary design that doesn't take up a lot of space and writes quite well. I don't think you could get a better fountain pen for the price.