I believe it works. Got mine for Christmas last year. The first day I used it I had three deer right under me. My stand is only nine feet off the ground. The deer never knew I was there. I have had deer that close before and not spook but really smell the air as if something wasn' t just right. With the sent lock they didn' t even check the wind. Even with no wind gravity will pull your sent down to the ground under you as the air cools in the evening. Even if it is not 100% it gives me a little more confidence that could be the difference.