They don't make them with the mechanical hygrometers anymore, just the round digital.
I definitely dig mechanical and no batteries and the ability to calibrate.
I think these are the gauges they used in their lids.
View attachment 2168855
Just to make sure the bag is doing its job, I probably won't put 1 in every bag. I never put 1 in every jar but rotate them weekly.
I bought ounce and 1/2 oz bags so I don't have to expose more then I need to when I need to refill my personal bag. The Grove Glassless Jar I bought is what I'll transfer my personal into, it has a heavy duty zipper that can take the abuse of being opened a bunch and the way my girl smokes, I definitely will need a heavy duty zipper. Actually, probably don't even need a zipper at all, it won't stay closed long enough to matter lol