Itech won't send you replacement foam kits for their masks. They say that all kinds of bad things will happen if you replace the foam...the certification will be void, brain sucking leaches will drain your IQ and make you vote Republican at 19, or your head will pop off during a penalty shot. Bad, terrible things.
Nash Sports & Majer Hockey sell replacement foam. You'll have to cut it yourself, but it's not rocket science.
There's lots of threads on how to replace the foam and what products to use to glue in the new foam. Steer clear of Gorilla Glue (trust me on that one, that's the voice of 2 weeks of peeling glue off my hands!!), and check out Plumber's Goop & contact cement.
Good luck
