This patented feature is something completely unique in the knee pad market. It offers a dual density foam core that allows your knees to gradually sink into the padding. The top layer of memory foam is a lower density layer that slowly absorbs the pressure from your knee. After your knee sinks through this top layer, the bottom layer of energy dispersing foam has a higher density structure, which provides a more supportive layer of padding. By combining the two layers of foam with gradual increasing levels of density, you will experience a progressive resistance cushion offering comfort and prolonged support.