OK I cut open one of the Ecogard X4011 filters tonight. It is spec'd for a variety of GM vehicles made across about 20 years. Here are the pics with a few notes:
I always mark the month/year of manufacture on the box in order to use oldest filters first:
I cut off the base plate with a disc grinder, good practice doing the hamfist
But watch out for razor sharp edges!
Contents: baseplate with gasket, ADBV, filter media cartridge, spring, can. There is no bypass valve - the bottom of the cartridge is a solid plate of metal (sorry no pic of the bottom):
Lots of good sized holes in the metal core tube:
These last 2 are not very clear (sorry) but are only intended to show the spacing of the pleats - there are lots of pleats and the spacing is pretty uniform - the first picture shows the widest spacing and the 2nd picture shows the tightest:
Comments: the can is very strong and sturdy, not easy to squeeze and not thin or weak as I had suspected. So it took a lot of grinding to cut the base plate off. The base plate is not the heaviest I have seen but it is good. The ADBV is flimsy but none is specified for my particular application so no matter there. I am surprised that there is no bypass valve - it's a bit concerning as there is no way for the oil to get through the filter quickly in the event of media clogging or if a cold start is done at very low temps (where the oil is thicker). I don't live in temps below about 32F and my vehicles are garaged at home, so again, no matter there. The core tube is metal with lots of big holes so flow should be good. I tried to twist the metal end plates off the media cartridge and could not, it is solid. The filter media is the typical paper type media, but there's lots of it. The media is glued to the metal end plates and there was hardly any excess, looks like a good job there, none of the paper edges were loose in the caps.
Overall it is a very good filter for the $1.86 that I paid. Again I did not buy them to use them as filters, I bought the cheapest filters I could find because I needed the base gasket, which did not fit the aging premium filters that I plan on using next. But these are good enough that I am comfortable running them for 5,000-mile intervals.
Hope this helps someone.