Product review (4 stars): Does not work as expected with a mini-dryer
I bought this directly from VentWorks as they had free shipping.  It is heavy duty and made very well.  Just wanted to let all know that if you plan on using this with a mini-dryer (NewAir, Panda, MagicChef, etc.), that they do not blow hard enough to open the back-draft damper, so you will need to rig the damper open and cover the hole to prevent critter/insect infestation.