Great Price, for a Great Product!  Comes fully assembled.  Slide it out of the  box.  Open it up and place on your boxspring or slats. “Done”.  Made my firm mattress even firmer without affecting the comfort level I love about it. Solidly built and DOES WHAT ITS SUPPOSED TO DO!  It helps your mattress retain its firmness while keeping your mattress’ original comfort.  I’m loving the  better nights sleep.