It looks like mess backed full synthetic media. If it's 97% at 20 microns then it's pretty good.
Did you try contacting Mercury to see if they have more efficiently info?
Haven't bothered the mercury rep with stuff like that - I may float it out to some of the boating forums to see if a rep can pick it up but I don't want to call my Merc rep for something like this yet.
Im just not running it till I know and I have plenty of good option Mainly the new HP4 at these HP's/pressures, and sump intervals.
When the guys ask about it - Ill just point out what I can see- which isnt great.
The can is nice and thick - probably the thickest Ive seen in a while.