It is very firm,not sure about the fiberglass.
I'm not aware of any fiberglass. I believe they are pocketed coils & mattress is very firm.
It is very firm. ?I got the queen but assume all the same other than size. ?No fiberglass.
Feels firm. Researched for hours. Am very pleased!
Yes, it feels firm. ?I think that's why many people buy the thicker one with more latex on top. ?I have no idea about fiberglass. ?I sure hope there is none.