For me, the envelope was in strong wind at the end (used for my Wäaschespinne Leifheit) unfortunately flown away. This was because the zipper, the because it is sewn over almost the entire length of the sleeve and thus actually Drüber evert substantially simplified had completely opened by the Windgerüttel. Definitely could be avoided if at the end of the zipper a small fuse (maybe Velcro?) Would be present. Since the shell is designed for its diameter rather for an umbrella, I should before buying a conventional clothes dryer weigh whether I grow me this envelope because they visually seen the spider makes more conspicuous because of (a spider) to great dimensions ( Length is Ok, diameter more suitable for parasol). With the large envelope to the slender spider for my taste to a ugly green monster in the garden was. And acoustically (Windgeknatter) was the shell because of their "excesses" in our striking (with stronger winds, as he was watching the end of March 2015). So nothing definitive for areas with a lot of wind as on the coast ....
