Hi, we have the Serta Blackhawk mattress in the GTXL 352 we recently purchased. I also love it. I wanted to purchase one also. I can't find any replies to your question. Did you have any luck locating one? Thanks!
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Mitch & Debbie
Maggie, the Wonder Dog
2015 GeorgetownXL 352
2016 Jeep Wrangler Unlimited
We got the upgraded Serta in our 2014. It was good until it wasn't. Last winter in AZ it no longer gave good support. It went to the landfill last month.
We had used it less than 100 nights before it was no longer good.