Just what my granddaughter need and wanted to put on top of her 18" dura metal slat frame.  It arrived exactly  on time and was amazing to watch it extend to its full size.  I bought a good mattress pad to go on top of the mattress but we felt we didn't need a board between the frame and the mattress.  She loves the mattress, says it is super comfortable and now gets the best sleep she has ever had.