Hey there! I designed and use these caps at work. These caps are designed to snuggly fit over a 3/8's concrete anchor with a little bit of threads sticking out of the nut. At work we use these to cover the anchors on metal handrails that we fabricate. I print these out of Bambu Labs TPU 95A HF. If you can use a filament dryer, I recommend it. You don't have to but, in my experience, if you do a bundle of them, they might be some strings here and there. I also print them with supports, you don't have to but, I do it for reassurance. The 3mf file that is also attached is for a set of 20 caps. I like to do this many at one time because if something happens to the print, you're not out all that extra filament. Again please, please, please, let me know of any feedback you guys have. It truly helps me in my 3D Modeling.