This hook is designed to hook into a 19.5mm diameter tube, held about 85mm away from the wall, but it can work with anything from about 55mm - 93mm distance.
Our towel ladder rungs were spaced too far apart for all the other designs I could find, so I designed this one to discreetly make contact with the wall behind the rail in order to keep the hooks stable.
So far they hold a damp towel just fine, not sure what the maximum weight is yet.
Printed here in Galaxy Black Prusament, 3 perimeters, 3 top, 3 bottom, 15% infill.
The author marked this model as their own original creation.