[cwl1979]

I'm  a curious person, have you looked at what you got? Your invoice says bellows. That would say to me it's just the rubber sleeve. Would be interesting to see what if you got the complete airbags assembly. If so that's a great price.
I used https://www.truckandtrailer.parts/ to replace all my Firestone bags with Contitech.

Hi Carl, On my rig 698 ZFer I can replace just the bellows. The
top and bottoms are permanent bead type seats, it uses those surfaces to create the air seal.   

Thats pretty cool. Glad you saved some money.