Ventair Mixflow Installation And Wiring Instructions page 4

Duct work connection should be made with duct tape or duct fast-clamps
(available through your local distributor hardware retail store) to ensure
a good seal and secure connection.
INSTALLATION-Applications,Recommendations&Wiring
Installation tips:
Figure 1.Typical Appliations
:Model:VMFIL series
Multi-Point Exhaust System