They are different in size and design details.
Magna is 100mm in dia., Immanis 110mm in dia.
They are of the same general visual design, but different in details of the headspring design, headband stitching, headband click-stop buckles, grille design and plating.
Immanis package also comes with a STAR-8 cable.
R² driver has almost 29% greater surface area than CA-1 driver, or the same s.a. as SR-1 driver.
R³ driver has almost double the surface area of the CA-1 driver, or 1.45x the SR-1 surface area.
The differences in R³ driver compared to R² driver, are 50% greater surface area, 2.5dB higher sensitivity, larger front chamber (ear/driver).