I use to have a gap between the door and the floor. This result in AC escaping the room quickly.I put this seal strip on my bedroom's door, it helped keeping the AC in the room to stay longer so I no longer need to turn on AC as long as before. This helps save the electric bill.

I read some reviews before buying, a lot of people complained it didn't stick.But I bought it with the idea of giving it a try, my seal strip works well.

For those who have been disappointed with adhesion, it's VERY important that the door be clean and free of soap, fingerprints, or any other contaminate. And, be sure it's dry. DON'T TOUCH the sticky part with your fingers. 

My seal strip has remained in place for about 2 months now with a perfect seal. Now my problem is solved!