The Ultramax II works on a standard 12" rough and is a standard installation. If you are thinking "Unifit adapter" then you're thinking of a Carlyle with the skirted bowl. The Ultramax II uses the standard watercloset flange in the floor, standard closet bolts and wax. You can pull it out of the box and stick it on the wax. If your flange is lower then the finished floor, you will need to stack two wax rings.
The MS604114CEFG Ultramax II is listed this way
C = Cyclone flush (Double Cyclone)
E = 1.28 gallons per flush
F = Universal Height bowl
G = Sanagloss