I have used some of those alosaks and they aren't worth the money you pay for them. They simply do not work. The seals are no good (I have had things get soaked in them). At the present time I will just stick with my bear canisters when I am some where that you may suspect bears are present. Like the last poster said even if you do have odor proof bags the bear will smell you no mater what and I am sure that where most of us trek the bears have seen a many a hung bag of food and he knows exactly what they are. These animals are by no means stupid and they have an uncanny way of figuring things like that out. I have seen it happen. We were once in the Smoky Mountains (many years ago, in the seventies) we had a coleman cooler that was made like a refrigerator with seal, locks and all. We had store this cooler inside our truck as our truck was very near the campsite and the bear almost tore the top of the truck off trying to get that cooler. She had two cubs and was relentless. We finally had to wait until she moved a distance away and we took the two chickens that were in the cooler out and left them for her to get because she would not leave. When we did that, she finally took both chickens and her and her cubs were on their way, thank GOD. She did serious damage to the top and both doors of the truck and it had to have serious repair work whenever we got back to town. We later had a visit from the ranger and he was making us aware of the fact that there was a crazy bear wondering around up near our camp site and we just looked at him and "yeah we know". It was all just a little scary...sabre11004