Clamp to mount a short (or long, I suppose) section of PTFE tube to a 2020 extrusion. I use it to feed the direct drive on my Ender 3. It allows you to keep the spool somewhere other than on top of the frame, to reduce vibrations, and still feed plastic from the top down.
You'll need 4 M3 heat-set inserts, 4 M3x12 ( i think, somewhere close should be good enough), 2 M5x8mm bolts, and 2 M5 T-nuts.
The clamp is designed to work with Capricorn XS tubing (3.95 +- 0.05mm OD) but should work with just about any tubing (Most are in the 3.9 - 4.1mm OD range, and this clamp has a 3.9mm opening. If you find that it can't camp your tube tight enough, a tiny piece of electrical tape on the inside of the clamp should do the trick