Queen split box spring only. I purchased this from the 1961 broadway location in nyc. The cardboard eventually sagged leaving a wooden t supporting our whole mattress. I didnt want another cardboard box spring nor did i want to invest thousands in one that isnt cardboard. Nucs generally are designated as 1 frame 2 frame etc with 3 frame being the minimum viable size if the temperatures are expected to approach freezing.
The associate that assisted me in the purchase of this box spring was excellent. Buy zinus jayanna 9 inch high profile bifold box spring folding mattress foundation strong steel structure no assembly required split queen.