Looks like it's just a plastic bag waiting to be filled by condensation. If you can't afford better, i'd say, go for it, but if you can spend a bit more, i'd look into the goretex bivy, or an e-vent bivy. I have a goretex British military one, and it does fine, but i do experience a bit of condensation in it in just cool weather. Am looking to get a e-vent one, when i have the funds and can get to the store to get it, because it breathes better, packs smaller and is lighter.