[en] A study to compare two thickness values, 0.125 and 0.250 in., of five materials, GE RTV 630, HS II Silicone, Polysulfide Rubber, Sylgard 184, and Teflon, for their shock mitigating characteristics with a split Hopkinson bar configuration has been completed. The five materials have been tested in both unconfined and confined conditions at ambient temperature and with two applied loads of 750 μ var-epsilon peak (25 fps peak) with a 100 micros duration, measured at 10% amplitude, and 1,500 μ var-epsilon peak (50 fps peak) with a 100 micros duration, measured at 10% amplitude. The five materials have been tested at ambient, cold (-65 F), and hot (+165 F) for the unconfined condition with the 750 μ var-epsilon peak (25 fps peak) applied load. Time domain and frequency domain analyses of the split Hopkinson bar data have been performed to compare how these materials lengthen the shock pulse, attenuate the shock pulse, reflect high frequency content in the shock pulse, and transmit energy. These materials are used for packaging of electronic equipment use with such mechanical systems as penetrators, nuclear transportation casks and laydown weapons