These are Groco's newly designed plastic poly filter baskets for their raw water strainers.
As of Jan. 1st 2016 Groco's raw water strainers will ship with newly designed filter baskets. This change creates a much more streamlined series of replacement baskets with many fewer part numbers.
The new baskets have an improved handle design which you will be really happy with. Sale of the old style baskets will cease as soon as supplies run out.