Mine have arrived, I've got:
C48, Red, 2.0mm (uncut weight 67.40g)
C53, Black, Ultramax (uncut weight 75.42g)
As Sherwin mentioned, they're hardly tacky. Less than any Rakza Z I've ever had, less than D09C, and a little less than Hybrid K3 (my sheet of K3 wasn't very tacky). The only rubber I've used which looks similar is Donic Bluegrip S2, which was similarly *just barely* tacky and came with the same grease-proof-style protection sheets.
Unlike BG S2, these have a bit of reverse dome out of the packet and have really short pips under the topsheet. They don't have the same booster smell that you get from R48/R45 (or the original Rasant series, if you remember that).
From top to bottom
Rakza Z
Rakza Z (I meant to put RZ EH here, but picked the wrong sheet up)
Rasanter R45
Hybrid K3
Bluegrip S2
C53
C48
K3 is the only one with comparatively super-small pips, but the C sponges are more porous (and have the reverse dome),