Poorly designed piece of junk. The engineering on totally lacks fundamental physics. I bought a king size bed, the center support legs are basically 2 weak sticks for a bed this size. Naturally, it could not support a decent mattress. The center support legs broke while we were asleep (total human weight 300lb). 
Even worse - The helpless Wayfair support suggested they could at best "try" and contact the manufacturer to send more of the same junk weak sticks for center support.