Trekmates Bivvi Bag - waterproof sleeping bag cover black 330g

I have used this very recently during a short walking holiday in the Alps. I found it rather narrow, but the length was good. However, there was a heavy storm one night and it offered no noticeable protection against the downpour. In my experience this kind of breathable fabric does not offer enough protection for serious sleeping out. In any case, this Trekmates bag did produce condensation, so it was not very satisfactory on that score either. Thirty pounds, which was the cost (roughly) is not expensive, but I would not recommend this product for bivouacing in mountains or in wet weather.