That is a 64k RAM upgrade for the Atari 400 computer. The switches each control an individual 16k block of memory, and would be toggled on/off depending on the needs of the particular program. Having all four on would let you play Star Raiders at 120 FPS! Unfortunately, they used a cheap fan and it was prone to overheating. I burned mine out trying to do a speed run on Sammy the Sea Serpent. Good times...