Sakura Craft Lab 007
Design forward Japanese machined pens. All are twist action. The 007 feels a bit lighter than the rest. I like how it shares a lot of the same design elements but looks different enough to be interesting.
Variants: Each numbered pen edition is very different from each other. Each comes in a range of colors. Some come in aluminum or brass.
Refill depending on variant: Most take proprietary gel refill in various lengths. Pen specific refills are available from the factory. A known hack is the Sakura Ballsign ID refills fit when cut to length. The 004 multi pen takes D1 refills.