Spillproof, just not while filling them up 🤣 (obviously). I much preferred this model to mall y of the other options about there. I did plate 1 with the main 5 holders and it printed in ~2.5 hours in my P1S compared to some of the designs out there that print in 8/9 hours. Be careful when inserting your hygrometer! I installed mine upside down initially and had to get a knife to pry it up (because the fit is *chefs kiss*) I’d recommend you put the lid on before installing the hygrometer, then the little loop/tab on the lid is the top. without the lid it can be hard to determine the orientation of the main body. Or just know that the notch on the back of the main body is the bottom. (not a modeling problem at all, just a useful tip to the end users).

Printed perfectly with print in place threads for the M6 connectors