Tested and working in both the Atari 400 and the Atari 800 computer, this 32k ram card will upgrade your 400 to 32k without the need for soldering, or replace two 16k cards in an Atari 800 computer (installed ONLY in the middle slot with a 16k card in slot 1) and still allow a full 48k. This is necessary for some esoteric upgrades like the Full-View 80 80-column board from BIT 3 Corp.
I found this card in an Atari 400 and replaced it with a 48k board of my own construction. It is tested as of 05Jul2024 to be working beautifully in my Atari 800 bench machine.