Can anyone tell me what type of files these are, and if they work in Lumberyard?

Working on a project with a friend and he sent me these files but I’m not sure how to open them. They’re 2A, 3A, 4A, etc. How do I open/work with them? Anyone know?

That is the compiled texture for Cryengine or Lumberyard. Try to download Star Citizen DDS Split.

I tried googling but this is all I found:

Is that what you’re talking about? If not, can you please link me the Star Citizen DDS Split program?

Yes. Just drag the folder containing that files on dds split execution and it will automatically convert it to tiff.