The Berkeley Ergonomic coil mattresses sold here contain a LOT of synthetic Polypropylene in case the sales people forget to mention it.

All the other mattress components are listed and described on their web site in detail but the synthetic Polypropylene is omitted. I would think that Good Night Mattress would want their customers to have all the information, so maybe they will add this one missing component so their descriptions on their site can be complete.