(1) use bonnel spring system (2) high density foam (3) good quality cotton fabric Memory folding foam mattress CD-Mattress #MYY ♥ Immediately responds to your body ... ♥ Fabric option:cotton, polyester etc ♥ Foam option: High denisity foam ♥ Spring net:Pocket spring, Superlastic spring, Bonnell spring ♥ Accessories: Latex, Memory foam, Coir fiber, Palm fiber, Polyester fiber ...