This is a printable Railcore Electronics Box Bottom Panel with Keystone Jack designed to slide on, so it doesn't require bolts but still has bolt holes if you want them.
I also included a version without the keystone jack, labeled *_NK.
This design was inspired by
Railcore Electronics Box Printable Bottom Panel by lostapathy, but isn't really a remix as I didn't copy or modify his model, but recreated something similar.