Not as advertised.  I purchased a queen size [Stratford] 8" coil mattress in January 2023.  Item does not function as described.  Mattress is supposed to have a  special "hinge" to allow clean bending of mattress at transition from seat to back.  The mattress I received did not function at all as described.   Mattress would not stay in sitting position, the mattress cover bulges and pops up at bend, nothing at all like the clean crisp bend shown in photos in advertisements.  Trying to return item now... looks like it'll be another battle to get rid of this thing first then find one that actually works as described.