These work ok for the most part. You have to be careful and not fill your container too full, otherwise the stored product will "evade" the diffuser and get pulled into the vacuum machine. They do their job if the container is not overfilled, so just a word of caution. I have several installed on my powdery stored goods and only one gave me issues; I think it had too much of the product in the container, so not a failure of the diffuser. Overall, a good safety net if you keep alot of flours, salts, spices, sugars, crumbs and such in your containers.