The flex foam X is pretty great stuff. It is pretty resilient. If you really want to tear it you can, but it takes some effort. Just pinching it won't cause it to tear. I had a piece that I cut out for the wrist, and I was torquing on it pretty good and it wouldn't tear. I really do love this stuff. Almost all of my MKVI is flex foam, and I wouldn't go any other way. Definitely worth the little bit of extra cash. DEFINITELY! Oh, and the density of the flex foam is 10lbs/cu.ft., hence Flex Foam X. Flex Foam 17 is 17 lbs/cu.ft and Flex Foam 25 is, you guessed it, 25 lbs/ cu.ft.