Product review (3 stars): OK  venthood exhaust fan but could be better.
This external blower is not the latest exhaust technology but it does the job.  This is a squirrel cage blower in a fairly primitive sheet metal housing.  Parts have sharp edges.  Mesh screen and damper were crude.  I would have bought a Fantech, turbine type blower but didn't have the right cfm in the 10" duct size.  I know from my latest leaf blower and cooling fans that better blower designs can be built to run quieter and more efficiently.