I really wanted to like these, but I found myself cursing at them as I tried to put the caps on them. The tolerances are so extremely tight. One single tiny misplaced fiber and it goes from very difficult to nearly impossible to twist shut. I wish I hadn't printed 10 at once. Printed in PLA on x1c - so unless i did something extremely wrong that I'm not catching, these things are way too tight, way too thick and extremely difficult to twist shut