Scent Blocker and Scent-lok are two different companies with two different approaches to scent control. The blocker does just what its name implies and stops a person's scent from getting out. Scent-lok absorbs a persons scent all together(in theory). I've heard that the scent blocker quits working after a few seasons, but this is just what I heard. I've had good luck with the scent-lok myself and haven't heard anything bad from other people. You still have to hunt the wind, but it's not always possible to stay down wind of these smart animals. I hunt a lot in Michigan's UP where its solid hard woods and the wind does nothing but swirl all day long.