This molecular sieve is great for drying hydrogen from your PEM electrolyzer. This molecular sieve 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 molecular sieve 13X, which will perfectly fill the canisters in the QL series generators. 

The molecular sieve can be reactivated by placing it in an oven for 1-2 hours at 230°C.