The RPF Ortho Pocket 800 Single Firm Mattress is a great buy, it comes with a pocket spring system. It offers superb contour support & as a result allows the mattress to form to each person's body shape delivering an extremely comfortable deep sleep. The mattress boasts side panel ventilation which keeps the mattress in great condition by allowing moisture control. The spring system is 13. 5 gauge & is caged edge to edge in a stell rod. Overall a great value mattress which allows a relaxing nights sleep.