Just about every stock intake has a baffle that is supposed to do that. What usually happens is they fill with oil, get cooked by the exhaust cross over and turns into solid carbon.
I remove them and use a milodon valley baffle.
https://www.summitracing.com/parts/MIL-32620Since it's not something you can see I prefer to use something that works.
But to answer your question, it's just a rectangular flat piece that covers the bottom, two self tapping rivets hold it in place, you can mock it up with poster board.