Asura Dynamics have released an Aluminium B30+B31 Side Mount Rail for a whole variety of AK brands out there!
These Include:
GHK,
LCT,
Marui,
E&L,
CYMA
If you're a big fan of the Zenitco style, then the B30+B31 Full Length Rail Set will make your AK incredibly tacticool. This will allow you to mount sights on top so I have a feeling that this will be a very popular product as a lot of people like to modernize their AKs.