Definitions for

**"Compression Deflection"**The measure of the hardness of a cellular rubber product. It is the amount of force require to compress a material a certain % of its original thickness. Typically, 25% deflection test results are used, given in pounds per square inch or kPa. ( ASTM D 3574-03)

PSI required to compress a given material a stated percentage of its original thickness.

PSI to compress lab slab a specified percentage of overall height, normally 25