The important issue with regards to the quality of the product is the weight of the foam being used in the cushion. This is usually based on the weight of a 1m x 1m x1m block of foam. The weight of this is 48kg in the case of the multipurpose cushion which means the cushion will not sag or give in over time and use. The hardness of the foam is a 30 in rating which means it is comfortable from the outset and will not get softer over the short to medium term.