Normal stem cells are. Excellent so I don't see why these won't be. I asked them ages ago about an XL version so I could keep a camera in it, they said it was in the works but never followed though. However I've seen they now say you can put a 750 ml Nalgene in so maybe a camera will fit.
Anyone have experience with the Alpkit stem cell dry bags?
https://www.alpkit.com/products/stem-cell-dry
Thinking about getting one to keep my battery pack in for charging my phone/lights/garmin etc while riding.