Product review (4 stars): Works Fantastic, BUT . . . .
Installation is not as straight forward as it may seem by the product description.  If you are not a completely capable DIY person you had best either get someone to help or hire an HVAC pro.
The one outstanding help was to be able to call the manufacturer and speak with the owner one-on-one and get his advice and assistance with installation.
The booster is paired with a simple inline lint filter and the probe is mounted on the dryer side of this filter.
Some have complained about 'back pressure' from outside turning the booster on when the dryer isn't running.  My response is simply to do one or two simple things.  Move the probe closer to the dryer outlet or unplug the booster when the dryer isn't in use.
I have no problems with my 'paired' system whatsoever and am fully pleased with the two products I bought and the help from the manufacturer, Acme Miami.  I did not call Tool King.
I would have given five stars but the initial confusion, until I called Acme, was a nuisance and slowed down the installation.
ONE BIG TIP -- BE SURE YOUR DRYER EXHAUST AND ALL INTERNAL PIPING IS COMPLETELY CLEAN BEFORE INSTALLATION!!