These are just some filler pieces for True Tiles tile bases. I created these so that I could print full tiles in one piece and make silicone molds of them. The original True Tiles have holes in the bottom and a very wide slot where the clip goes, which causes issues demolding.
These are intended to be put inside the base and printed with the tile and base, not printed on their own. They should intersect and they will fill gaps in the True Tiles models. If you aren't planning on making molds of your True Tiles, these probably are of no use to you. The pictures show how I use the fillers to print a full tile in one piece.