Suggestions as to what this equipment is ???

Wife and I are getting closer to closing on house with this system in the mechanical closet. I did not get a chance to get any info off of the control heads, but was wondering if you experts might be able to decipher what I am looking at here.

House was built in mid-90's, good strong well, not sure of water test results, but no noticeable odor or staining observed.

I know this isn't much to go on, but willing to listen to all ideas. Is this a dual softener setup of some kind? I would of thought the resin tanks would be the same size. Looks to me like they are connected in series, could the little tank be a filter of some kind? Other than the salt tank, I see no other tubes, hoses, tanks, etc. connected to these units.

Well, thanks for looking. ANy advice or comments are appreciated !

Autotrol controls on the tanks.
One looks to be a softener and the other is a filter of some sort.
A raw water test would give some light as to the filter unit.