Is this a mattress or a box spring?

It is a box spring foundation only. It sits under the mattress and adds support and a small amount of height.

It is 5.5 inches tall, which is a low profile compared with standard 9-inch box springs.

Which mattresses does it work with?

It is made to pair with Beautyrest Black mattresses, and its solid top also works under most standard mattresses.

It comes in Queen and California King.

Yes. It is a foundation, so it should sit inside a bed frame or on a slatted base rather than directly on the floor.

That depends on your frame. At 5.5 inches it adds little height, so measure your mattress and frame first if you want a taller bed.

5 stores we checked sell it, including Abt Electronics, Mattress Firm, JCPenney, Beautyrest, Raymour & Flanigan.

At JCPenney, for $300.00, as of our latest check.

$300.00at JCPenneyChecked 19 h ago

Compared across 5 stores. Prices are checked against each store and labelled with when. Store links may earn us a commission. Price via Klarna.

It checks today's price at every store, compares the alternatives and answers in about a minute.