It is the finalized version of the original Radian prototypes. After the sales of the return tops and receiving feedback from those who had seen the pictures and those who have played with/owned the prototypes, they decided to machine an IRG lip into the return top.
Thus, like the prototype, it is made from aircraft grade 6061-T6 aluminum and features the spiked hubs. This version, however, is anodized in a light blue and features the text, "SPYY RADIAN MKII," followed by the serial number of the yo-yo around the outer hub of the return top, or where the grind lip appears. The anodizing allows for smooth grinds. Some people say that this return top feels close to an Oxygene Oxy4. It retailed for $75 USD.
Radian Mk II: BBB Edition
The MkII: BBB Edition, or Black Bead Blasted, features all of the same features as the original Mk II except the finish. The finish is bead blasted and then hard anodized in black. This anodizing allows for an even slicker finish and longer grinds.
Radian Mk II Hyperion Edition
The Radian Mk II Hyperion Edition was like the original Mk II that was sold by SPYY and retailers across the U.S., except for a few things. This version featured more intricate laser engravings and was only sold at the 2006 Worlds.