We just had this unit inspected by Airstream Adventures Northwest including a brake check, roof inspection etc.(I can provode details of the extensive inspection). They also sealed the exterior of the unit using the only approved Airstream sealer by Walbernize ($495). It has the factory solar option and LifeLine AGM batteries. Equalizer hitch is included. Too many options to list but here is the 2018 brochure:

https://www.airstream.com/wp-content/uploads/2020/08/2018-Classic-Brochure.pdf