Product review (5 stars): Excellent to keep heat and humidity inside the house during the winter
so i bought this to replace my inline flappy door dryer vent which caused more grief than anything else by constantly falling apart. Im using this in the winter to put moisture back into the air and help lower my heating bills. It would be better if there was a mesh type screen with every vent to catch all dryer felt bunnies prior to flying out but that can be easily retrofitted.