1.  What does 5.2 lb density mean?
      
The weight and the visco-elasticity of the foam are determined by the amount of chemicals used in the composition of the polyurethane foam. Generally the higher the density, the greater the visco-elastic properties exhibited by the foam. The density does not determine the firmness of the foam. The ILD (Indentation Load Deflection) rating is the specification that determines firmness. Most inexpensive foam products seen in stores are made of only 3-5 lb density foams that do not provide the same visco-elastic properties as the 5.2 lb foam.

      
2. What is ILD (Indentation Load Deflection)?
      
The ILD rating tells you how hard or soft the foam is. The higher the ILD rating - the harder the foam. The ILD rating is the number of pounds required to achieve 25% compression of a 4 foam using a 50 square inch indentation. Therefore the 14 ILD foam requires 14 lbs to acquire 25% compression. For comparative purposes, Tempurpedic™ name brand foam has an ILD rating between 14 & 15.