My XJ came with the towing package which included the aux cooler. The line coming from the radiator to the aux cooler (part of the kit) is starting to show it's age. I was able to find one on eBay that was NOS.

Date on the sticker is 03/12/98. Still sealed in the original bag.

 

24 years young. Good thing rubber dont age much!

 

I think it was hermetically sealed in a mayonnaise jar. And 10 years younger than my XJ!

 

Most likely a mayonaise jar of pure argon.