This silica gel is great for drying hydrogen from your PEM electrolyzer. This silica gel is specifically intended as a replacement for the QL series hydrogen generators, but can be used as a replacement in other systems as well. One unit is about 175mL of indicating silica gel beads, which will perfectly fill the canisters in the QL series generators. 

This indicating silica gel will turn from blue to pink when saturated with moisture. The silica gel can be reactivated by placing it in an oven for up to 3 hours at 120°C.