Needed a closed hook for the Ikea Kungsfors towel holder:

https://www.ikea.com/de/de/p/kungsfors-stange-edelstahl-00442499/

Printed in PETG for outdoor use. On the photo the hooks are 3 years old and hold up really good.

Used for a outdoor playing kitchen with sand and water for my nephew.

Tolerance is quite tight so they doesn't slide around a lot, depending on your printer tolerances you may need to scale them up to 101% or 102%.