Product review (4 stars): 5 star idea. 3 star design
This thing is a great invention. It warms my house when my heater can't keep up with the cold. My problem: 4 days after installation, the cheap little plastic hinge cam off. I duct taped it shut until I have time to take it all apart and reinstall it. Its ok to charge a little more and design it with PVC or a metal hinge to keep the trap door in place. I will be very happy with it after I modify it a little.