HT820 Firm 12 - 20 5 Gray + + + + + + N/A N/A Closed Cell Silicone Foam with Smooth Sur ace, UL94V0 HT840 Extra Firm 16 - 26 5 Gray N/A + + + • + N/A N/A Closed Cell Silicone Foam with Smooth Sur ace, UL94V0 ...