Hi Spruce,
If that's the same as one I tried years ago, it's absolute rubbish
The alloy screw is hollow and made of extremely thin alloy and attached to the plastic by prongs of alloy crimped through - the one I tried fell off as I was trying to screw the gooseneck on to it.
The Gardiners one is solid alloy and is a fairly good fit in the Unger pole, we just drill and put a retaining bolt and nut through the end of the pole and the neck of the pole end screw.
Then we drill a hole on the skew into the top of the pole so we can draw the pole hose through.
Thanks anyway,
Ian