The Southerland Cobalt Extra Firm Mattress is a extra-firm innerspring mattress built for stomach sleepers and plus-size sleepers needing maximum lift. Southerland's Scandinavian collection layers gel-infused memory foam over an offset-coil unit for cool, supportive sleep at a working family budget. At 13", it sits in the standard profile range — generous enough for adjustable bases yet still easy to sheet.
A foam-encased perimeter lets you use the full sleep surface — and sit on the edge to dress.
A reinforced center third keeps the spine aligned across every position.
We deliver, set up in your bedroom, and haul away your old mattress — no extra charge.
A 9/10 firmness — supportive top with minimal contour. Best for back and stomach sleepers, plus heavier sleepers who want less hug.
Built for adaptive support and breathability. Every layer is hand-checked before it ships from our warehouse.
Quality sleep at the best value
With roots tracing to 1893, Southerland’s unending commitment to its customers and business partners has allowed us to grow into one of the largest and most respected bedding manufacturers in the United States. Because America sleeps on Southerland, we think it’s important that our sleep systems are made in America.
Certifications
All the foams in this mattress have environmental certifications that ensure they are safe and non-toxic. Our polyurethane foams (memory foam, transition foam, and poly support foam) are CertiPUR certified.
