... 3.renewable,indicate humidity; 4.customized packaging; About Silica Gel Cans:1.cobalt-free silica gel;2.tinplate box pack,beauty ... silica gel as raw material, the body covered with small holes solid aluminum cans as a container, the product compression and ... and resistance to drop the pressure high temperature.2, Aluminum cans with a new tinplate manufacture, surface treated, smooth not sting, but ...