I got replacement filters for my Shark vacuum cleaner, the old ones are clogged solid because I forgot I need to clean them.
They arrived vacuum packed which seemed odd. When I unwrapped them they were only 1/4" thick instead of the 1" or so of the old one, I thought I had been conned.
By lunchtime they had grown to 1/2" and by evening the full 1", clever people these Chinese.
This may be common knowledge to the group but first time for me :-)