The QUAD 5 ALL is our most premium system featuring a 5-zoned ergonomic design with max resistant coil edge reinforcement wrapping the entire mattress for 360° of support and comfort. By utilizing 2 zones of firmer coils under your lower back and knees, the system provides targeted support where it is needed most. The other 3 alternating sections are designed to give less resistance to help maximize conformance and pressure relief at the shoulders, hips and feet.