These Bear Resistant Containers are top quality. They are expert tested (by bears), and have proven very effective in not only reducing odor transmission of the food inside, but also in keeping even the hungriest of bears out of your food supply. Backpackers' Cache - Bear Proof Containers are approved by the Sierra Interagency Black Bear Group (SIBBG) and the Interagency Grizzly Bear Committee (IGBC).