The Pilot G-Tec-C is legendary amongst pen fans. Essentially it's a range of extra-fine needle-tip gel rollerball pens. The reason people love them so much is that not only does 'extra-fine' actually write a really fine line, the refills write incredibly smoothly and contain top-notch bio-polymer gel ink. The most well-known example in the UK is the Pilot G-Tec-C4 (in Europe the G-Tec-C designation tends to be used instead of Hi-Tec-C, but they're the same thing). G-Tec-C4 is an ultra-fine 0.4mm rollerball writing a 0.2mm line in a choice of 10 ink colours.
