Some days ago I published a review on a remarkable Spanish pen—the Súper T Gester 20. After using it for a while I ran out of ink and proceeded to clean it. This was very easy despite the fact it is a piston filler. The reason, as I pointed out, was that section and barrel attach to each other by a simple thread.
What I had not foreseen was how easy disassembling the piston was. Once the section is out of the way, the piston comes out of the barrel unscrewing the knob further. And that is it!
Easy to disassemble and easy to clean. There are no internal sheaths or hidden screws. In a sense, this pen is an eyedropper with a piston, a very easy piston.
Hats off for the designer Manuel Portus Ribas.