1. IN A MATTRESS CONSTRUCTION WHEREIN A PLURALITY OF COIL SPRINGS ARE ARRANGED IN SIDE-BY-SIDE RELATIONSHIP WITH THEIR RESPECTIVE AXES DISPOSED VERTICALLY AND WHEREIN A COVERING IS PROVIDED FOR THE TOP, BOTTOM AND SIDE WALLS OF SAID CONSTRUCTION, THE IMPROVEMENT COMPRISING A STABILIZER FOR SAID CONSTRUCTION, SAID STABILIZER INCLUDING HORIZONTAL TOP AND BOTTOM PORTIONS AND SIDE PORTIONS WHICH EXTEND INWARDLY TOWARD EACH OTHER, SAID SIDE PORTIONS COMPRISING RESILIENT MEMBERS NORMALLY URGING SAID HORIZONTAL PORTIONS AWAY FROM EACH OTHER, SPRING TURNS FORMED IN THE APICES OF SAID SIDE PORTIONS, SAID SPRING TURNS PROVIDING THE RESILIENT CHARACTER THEREIN, AND MEANS HOLDING SAID STABILIZER IN ASSOCIATION WITH A SIDE WALL OF SAID CONSTRUCTION, SAID SPRING TURNS DEFINING OPENINGS FOR RECEIVING SAID HOLDING MEANS AND INCLUDING A FLAT FLEXIBLE PLATE DISPOSED ON THE INTERIOR SURFACE OF THE SIDE WALL OF SAID CONSTRUCTION, SLOTS DEFINED BY SAID PLATE FOR RECEIVING SAID HOLDING MEANS FOR SAID STABILIZER, SAID SLOTS BEING ELONGATED WHEREBY SAID HOLDING MEANS SLIDE RELATIVE TO SAID SLOTS WHEN SAID CONSTRUCTION IS SUBJECTED TO PRESSURE.