The Shore and Asker gages are commonly listed material properties (as hardness) on Gap Pad data sheets. The hardness value should not be confused with modulus or stress-strain behavior. Modulus and hardness do not necessarily correlate to one another. Modulus is the ratio of Stress and Strain. To understand the Gap Pad characteristics, one has to look beyond the hardness value and instead, compare the modulus among the Gap Pads instead.