When I purchased my sons bedroom set 4yrs ago it needed a bunkie board ( to this day the furniture store has FAILED! To order  deliver after multiple request) from day 1 the mattress would sink in the middle even though it had wood slats. And not because of sons weight he is 118 5’12.  This is a long term purchase even if we ever swap bed sets since it also works as a box spring. Thank you Wayfair!! As always absolutely no disappointments!! My 17yr old son put it together in about 20min, it includes tape to hold the mattress in place. Delivery was right on time with no box damage.