What I observed
I took the Tumella umbrella outside in light rain and mist for the video below. Its canopy looked flatter than the umbrellas I was used to, and the patterned underside stood out when I opened it. The button opened it quickly and with noticeable force, which made it easy to get under cover without fiddling with the frame.
Water beaded on the canopy during that outing. After coming inside, I could shake off much of the water. The included sleeve had enough room to slide over the folded umbrella without carefully threading it through a tight opening. I also noticed a vent near the top of the canopy.
What this test cannot tell you
The rain was light. I did not test the umbrella in a downpour or a measured wind test, and I have no long-term durability result from that video. I also did not measure UV protection or verify the current warranty terms. If those details matter to you, check the current product listing and warranty before buying.
For a compact automatic umbrella, the fast opening and easy-to-fit sleeve were the useful details I could demonstrate. The video shows the umbrella I handled; check the current shopping page against it because listings and variants can change.