This is the square shaped drop in filter for your oem intake for better/cleaner airflow. It's a K&N Filter so the name basically sells itself. I bought it and as I was installing it my friend told me he'd sell me his CAI because he wants to put his car back to stock and since I opened it I couldn't return the filter so it's brand new just opened.

I paid 55 but I'll take any reasonable offer

 

what car is it for?

 

b5 a4 1.8T im not sure if it fits on the 2.8 models too