This is a simple towel hook that hangs off the top steel rail of a Coleman Power Steel pool. I designed it for my 22' pool but I imagine it would fit other sizes as well assuming the top steel rail is the same shape and size. Printed in PETG with 2 shells and 15% infill and it's plenty flexible and strong enough to hold a heavy beach towel.
OnShape document link here.
The author marked this model as their own original creation.