I've been doing some research on this regulator as I've been wanting to get one. I chatted with the customer service for FosterandSmith today. They said that it was CGA 320 so it should fit on standard CO2 tanks. The 4-6 kg/cm comment is in reference to output pressure. 4 kg/cm is about 60 PSI, which is more than you probably need. I think you can use an allen wrench to adjust it down though.