Oxigen tanks under booth cover

[dadecasa]

Hi all, I am a new member here and I tried to search for the answer to my question in the forum, but no luck...

I am in the market for a 2nd gen XC90 and while inspecting one last week I noticed two small tanks under the booth's floor, where the spare wheel sits. I think they had "high pressure oxigen" written on them. When inspecting another XC90 today, I noticed that the two small tanks were missing, so I am wondering what are they for?

The owner manual does not mention these, does any of you have an idea?

Appreciate any insight.

Thank you!

edits: grammar

 

[NFAreview]

I'm guessing they are the tanks for the air suspension but it should be compressed air, not o2.

 

[dloftis]

Those are for the 4 corner air suspension which is an option when new ($1,800). We have that option.