and the and the industrial vacuum cleaner 50mm plastic screw thread friction ring. POSSIBLY THE LAST FOR SALE IN THE WORLD!!

It fits on the steel wand and a separate metal part screws over it and locks them together. It's under the knurled silver locking ring on the top of the steel tube in the foreground of the photo.

At the moment, standard postage is capped at a maximum of $25 within Australia, so maximise the saving on postage and buy something in the related parts below!