They're great for humid climates. We rented these by the ocean where we have had constant problems with salt and sugar and they definitely keep moisture out of the salt if you close the top right away. However, I have found that due to the flat top that the salt comes out of, the salt does not shake out as easily as with a domed or conical bottom salt shaker. Actually it's not that important. Just add a little more side-by-side to your shake. My only downside is that the price + shipping made them quite expensive for plastic. I looked at all the other options and knew that Tupperware plastic should last ten years if not mishandled, so I spent the money on something I hope will last.
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