The 3 Steps determine your results; it’s not a matter of counting cushions. Try One First and Test Your Results when inserted inside your zippered cover. CASE STUDIES found you need to measure your sag depth the same way you actually sit. NOTE: must have 2” of remaining foam thickness to compress for this to work. Less than 2” indicates your cushion foam is too weak or you have a weak spring deck. EXAMPLE: 6” cushion with a 4” sag while sitting has 2” of remaining foam. This foam product conforms to the support under it and is used to help restore sagging or weakened foam (not down) cushions but cannot compensate for a weak spring. While it may not be impressive or looks like common foam like polystyrene, it’s not. It’s chemically different and used in the aerospace industry. But, it requires expensive laser equipment to shave into different thicknesses along with a heat bonding process to create it. 2-ply heat fused material is used to make the 1.5” thick Extreme. This is the BEST ALTERNATIVE to replacing your cushion cores or the repair costs of an upholsterer. We are simply sharing what worked for us. If you call us, you talk directly to us, who manufacture this product and have dealt with this same issue for decades. You get the specialized foam material, instructions and the know how to do this, our technical support and all the benefits of Amazon. Most Negative Reviews come from those who ignore our instructions and lay it under their cushion or don’t have 2” of remaining foam. While it can’t work for every situation, 80% of those who follow the 3 steps are successful and can delay buying new furniture.