Gyro Air G-700: "Max air flow" and "Max air flow @4in hose" explained

Dust processors typically have two specifications for the airflow, one for the maximum airflow the blower will generate without being connected to any pipes, filters or other ducting system components at the dust collector's inlet, and the other for the "Real CFM" which is the maximum airflow the blower can generate when connected to a specific duct diameter i.e. 4" hose with filters attached to provide a more actual or "real" value that one can expect when configured similarly.

In the case of the Gyro Air G-700 Dust Processor, the max airflow at the 6" inlet is 1110 CFM and then once it is reduced to 4" hose, the real CFM at the end of a 10'-20' length should be about ~700CFM or slightly higher.