12-13-14-15 cm high 12-13-14-15 cm bagged springs with 250 springs per square meter available in ZONED (3-5-7 zones) and MONOZONE versions. Springs are available in wire diameters from mm 1.70 to mm 2.20. By varying the lift of each spring, it is possible to have three different versions of the springing: "HARD" (with higher lift), "MEDIUM" (with standard lift) and "SOFT" (with lower lift). The structure of this product is more compact thanks to the "Plus" system, two layers of anti-allergic polypropylene fabric glued to the supporting surfaces.