Laxinis World 4” Quiche Pans with Removable Bottom, Non-stick, Fluted Sides, Mini Tart Pans, Round Shape, Set of 6

Does the bottom of thr pan measure 4 inches by 4 inches or does the top? Trying to determine if the bottom is less then 4x4 before ordering ?

How much does it hold?

What Is the non stick coating made of, Teflon?

Air fryer safe?