Our Generators are offered in two models (Model B and Model C) and 8 different capacities. B Series Generators are geared towards providing the strongest airflow while maintaining cold temperature. C Series Generators are geared towards proving the coldest possible temperature while reducing some airflow. Generator capacities of 2 CFM, 4 CFM, and 8 CFM are compatible with our small vortex tube, while generator capacities of 10 CFM, 15 CFM 25 CFM, 30 CFM, and 40 CFM are compatible with our medium vortex tube. Purchasing additional generators is the ideal way to change cooling capacities on the go.