I am not sure whether this twins of S&W .44 Magnum M29 model guns has real gun version, but they are definitely very rare I can be sure.  Built by Kokusai, Devil and Satan are custom race revolvers made by normal ABS and available in either 6 inches or 8 3/8 inches barrel.  As there is metal insert in the barrel, the twins is very heavy by model gun standard.  By putting weight on the barrel without reinforcing the structure is the problem shared by both M29s.  I have heard a person who make a fast draw of M29 Custom from his shoulder hoster, he ends up having only the grip in his hand as the barrel was broken and left in the hoster during the draw.  So take extra care when you hold this gun as the rigidity is poor.
 
   

Rubber grip and adjustable front and real sight are shared items on both models.  As there are not much custom race model gun on the market, race revolver is more precious.  This is another model gun collectors’ item.