They are actually oversize for what they represent. All the hose ends are hollow, you might have to open them up a little, depending on the hose you use. The "tees" are to be used with the hose ends (hose attaches to hose end, hose end attaches to tee or other adapter).
Sorry to say, 3D printing can't make tiny holes too accurately (size or roundness). So I gave you a hole, albeit a bit undersize to start. I tried to show a typical assembly but I guess it wasn't too clear. Sorry you had some trouble.