The pen is a Spacetec by Diplomat, apparently you can write upside down and under water with it, although why anybody would want to do either of those things is a bit strange, but never mind the writing is the main thing. It works like an actual biro pen (in other words, not gel, not rollerball) - has a good weight to it which is nice to hold and I could also get light lines as well as heavier ones. According to the leaflet, it will write up to 3 miles before needing a new refill......so I could be sometime with this one then, lol.
and the sketches......
Overall, I'm very pleased with this new pen
ideal for sketching en plein air and needing to
hold the sketchbook at an angle....the pen kept writing, yay!