Did you try opening it in S3PE?
Doing that should give you a pretty good idea what it it is.
I just woke up, so I forget what the tags are exactly called, but If it has OBJKT whatever tags then it's an object, and you can click GRID to find out what categories it's in, and how many simoleons it costs. If it has MODLs you can see the 3d preview of its mesh in the model previewer, if there's no ICON or ThUMB that shows you what is is outright. If all it has is a IMG then it's a pattern or recolor replacement or something. If it has CLIP then it's a pose, of it has a bunch of COM or something it's a Lot, etc. Again, I forget, but you'll see when you open it.