The sieve is for separation of steel ‘media’ (small metal pins) from cases after a “tumber” cleaning method.

The top part lets the media through, and will gather the cases.

The bottom one gathers the steel pins, and lets the water through.

The sieve will fit a 200mm container - as my pan is exactly that size.

Watch out!

You need to keep the project files intact. If you remove the modifier from the bottom part, you won't get a sieve, just a plain solid bottom.