Quality; durability; reliability; serviceability: four special concepts that can always be associated with Pelikan piston-filled writing instruments, and they certainly apply to the beautiful, well-made M205 series of fountain pens and to the M205 "Duo" Highlighter fountain pen, in particular. One can be certain that these Pelikan fountain pens, with proper use and care, will last a lifetime.
Although it is fitted with a steel nib, and has less 'bling' than the more expensive M400 series, the M205 Duo is the same size and has, what appears to be, the identical piston-filler and the same ink capacity.
The M205 Duo Highlighter performs the way it's supposed to and the highlighter ink flows well. The translucent yellow barrel complements the yellow highlighter ink, and it's useful and fun to be able to easily see the ink level. A bottle of highlighter ink is included in the package, and additional bottles of the special Pelikan yellow highlighter ink are readily available.
Filling the pen is not difficult although instructions and a standard Pelikan guarantee booklet were not included in the package with my pen purchased through Amazon. Here's how to do it: 1) Un-cap the pen and rotate the piston knob at the end of the barrel fully counter-clockwise (the piston should be all the way down towards the nib); 2)immerse the nib completely in the ink; 3) rotate the piston knob fully clockwise, drawing ink into the reservoir; 4) now, expel the ink back into the bottle by rotating the piston knob counter-clockwise again (it is often necessary to fill & empty the pen a couple of times to be certain one fills it to capacity); 5) Fill the reservoir again by performing steps 2 and 3 again; 6) With a filled resrvoir and with the nib over the ink bottle, expel 4 to 6 drops of ink back into the bottle; 7) Point the nib up and rotate the piston knob fully clockwise; 8) With a soft tissue, gently wipe off any ink that may be on the barrel end; 9) Next, hold the tissue to the back of the nib (on the black plastic feed) for about 3 seconds--to draw off any extra ink in the feed. This clears the feed's air channels; 10) Lastly, gently wipe off any ink on the top of the nib. That's it! View filling the pen as a relaxing ritual and you will grow to love using your piston-filled pen.
Well-made, dedicated piston-filled Pelikan fountain pens that can only be filled from a bottle are, in my opinion, far superior to any cartridge/converter fountain pen, and, since Pelikan nib units are threaded, the nib units can be easily removed for cleaning--including thorough cleaning of the ink reservoir for color changes--or the nib can easily be replaced with another size. This feature makes the Pelikan eminently more serviceable and adaptable than a great number of competing writing instruments. Also, although primarily intended to be used as a highlighter, with Pelikan's special ink, the M205 Duo Highlighter can also function as a regular fountain pen when fitted with a standard width nib unit and filled with regular bottled fountain pen ink available in a wide-range of colors.
Removing a Pelikan nib unit is easy, and it's not messy if the pen is empty, although it can be accomplished with a filled pen. Here's how to do it: Hold the pen barrel with your non-dominant hand and, with your dominant hand, firmly--but not too hard--grasp the nib by placing your thumb on top of the metal nib and your forefinger on the feed (under the nib). Next, with your non-dominant hand, rotate the barrel (do not rotate the nib unit) clockwise to unscrew the nib unit. Do the opposite, rotating counter-clockwise, to attach. When reattaching, be sure not to overtighten. Just be sure that it's a snug fit (perhaps no more than four turns). If you grasp the nib unit with your dominant hand and rotate the nib unit, you run the risk of moving the nib out of alignment with the feed. That's all there is to nib removal.
Enjoy your Pelikan!