Nilfisk and Tellus GS82 and GM82 and the Nilfisk and Tellus GA71 GS81 and GM81 industrial vacuum cleaner lower container clip.
In the photo it's right at the front above where the hose enters the dust container. There are two on the GM81 and four on the early Nilfisk GS82 and GM82 Industrial Vacuum Cleaner but two on the later version.
We also used them to hold down the lid on some of the 205 litre separators we made. The one in the third photo has a locking ring on it, but if we hadn't had a ring, we could have used these clips.
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!