I think it's just is Ra-Tech product that hes drop-shipping. it's the only product on the websites thats it's specified 4-6 weeks to have it.
Maybe he's does it on all his gun (I can't confirm, I just bought the Ra-Tech stuff from him :P). But with the service he give, I have nothing bad to say on him. Good to see someone putting energy for a good relation with the customer!!
-KWC P226 X5
-Ra-Tech WE HK416