Aha. That’s an AC Delco cover for the retrofit so I see you got the regular 2 filter set. The Dorman kit has one that bends at some places as it goes up so it’s one piece. I’m sure they can use the 2 part filters too.My Esky did not have them from factory I retrofitted and installed 2 filters.
My guess is that you get more filtration with better overall flow with more filter area. They use 2 seperate filters as thats the only way you could slip them into that slot i'd imagine.
I ordered the following items
https://www.amazon.com/gp/product/B01G5VHFW8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 and
https://www.amazon.com/gp/product/B0010DW5ZO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
when I did my retrofit.
Mine Are 2 years old. Probably due for a change.
Edit: Thinking about it the wife has complained about a musty smell lately and air flow isnt great. Ordered some new ones.