This is a custom water bottle rack that's designed to stack and is keyed to align side to side.
There are multiple optional other parts that I will upload separately and link.
This piece can be used on it's own or with the other components to build a water bottle rack n wide x m tall.

The parts do not snap together, but are keyed. I used some hot glue to connect them together (the hot glue can be easily removed if you want to reconfigure). You can use other glues or remix to add connectors.

There is an optional part for the side that is fully flat (without the protruding web) and a part for the back if you wan to extend them longer to self support the bottles. I am able to position these close enough to the back of my shelf that the bottles are held up by resting on the shelf on their sides with their bottoms resting against the back wall of my cabinet.

I used Bambu PLA so have included that profile, but other filaments OK.