they havent been made in a long long time.
I think KSC made one at one point.
but I havent seen one for sale anywhere.
might have to get a rail adapter and just get a light..... considering the lam unit sucked balls
anyways found this thread that may be relevant
http://airsoftcanada.com/showthread.php?t=140354
or you can contact somebody in japan to look around *cough*barf*cough*aqua*cough*