Boat hook, 20mm, 25mm and 1" versions available. Models have 0.4mm tolerance, to fit over the pole, so 20mm pole has 20.4mm hole for pole.

Best printed as solid (100% infill) at 45 degrees with supports for maximum strength. This avoids printing upright layer lines where the high shear force is likely to occur.

The hook can be fastened to pole with single (preferable 416 stainless steel) screw.

If you need a different size, let me know.