Two pieces for paint jobs on work trestles. It is designed to be clamped on work trestles with 25x25mm square tubes. I think the majority of work trestles (a.k.a. saw benches) on the market should have these dimensions anyway.
The fine tip piece is optional. If you need a bigger surface for your work piece to stand on stable, then you would just use the clamp piece alone. If you want to reduce the touching area to the work piece while painting, you would optionally insert the fine tip.
Tolerances are tight, so you can just insert the tip piece into the clamp piece and the tip sits firm. To remove the tip, use a bit of force and rotation and it's off.
The author remixed this model.
This is a remix of my Wolfcraft 20mm Bench Dogs. The tip piece is exactly the same. So you can also just use that if you already have it printed from that other model.