Fel-Pro quality is Bean-Counter proof (means they spare no expense)
1) They are Fel-Pro gaskets.
2) See reason number 1 above.
3) The silicone material lasts longer and performs better than the cork style (from the 1940's thru the 80's) that always leaked and got brittle too fast.
And NO...I do not work for Fel-Pro, but sure believe in their products.