The dimensions correspond to what is announced for each format (40 * 60/60 * 80/80 * 120) and the thickness of 50microns is all it takes to have a good strength.
I made a small leak test: I filled a copy air of each model and 24 left as is. After this time, they were properly inflated. I put some pressure by hand and it can cope, once you start to really force it farts course, but the level of resistance of these small bags and zipper match perfectly with what I was looking for !
The food quality is another benefit when using these bags to preserve vape components thoroughly cleaned (drip-tip, ...).
In short, if you are looking for zip bags of very good quality, you will be served!