This is a 2020 extrusion 45 degree brace for a z-axis frame allowing you to use excess 2020 extrusion you may have as a brace to stabilize the z-axis.
In my printer (flsun i3 plus) it has made the z-axis rock solid, no play what so ever.
You need to print 2 per brace one for each point of attachment. I used m4 bolts and tnuts which you'll need 4 of per mount (8 per brace). I'm including the onshape design in case anyone might want to remix.
I tried to filet everything so you have nice smooth edges. I don't know if that is everyone's preference but it was mine. If you don't like it feel free to use onshape to make it to your liking. It took me a little bit to learn onshape but once you get the hang of it it is really nice.
I wish more people would include their cad source files with their things. Stls are great for printing but remixing not so much
onshape link: https://cad.onshape.com/documents/1c0c99293dba338972796a9c/w/dc0dbd890100640b0350c4ce/e/6b05427eaac6a5d037eba30e
this has to be the simpliest thing to print so if you can't figure out the settings you need real help. If you find the piece to weak increase the infill but 10-20% should be fine