I have the nh app and I don't really know how to get pics on. But if you have seen the felt bumpers at lowes (they are 3/8s) they look just like that but there silicone domes
Your last posts have demonstrated no desire to look up anything, as a Google search for "stl" "what do i do with stl files" "how to print stl" "make 3d stl" all reveal enough information within the top 3 results for you formulate much better questions.