I think the ones we used were the Rab storm bivi bags. Very very happy with them, stuck a self inflating sleeping mat (400 grams, well worth the weight) and sleeping bag inside and I could have slept anywhere (apart from that bloody bench!!)
They are quite breathable as well but I never bothered doing the top of the bivi up as it was quite warm.
I think the ones we used were the Rab storm bivi bags. Very very happy with them, stuck a self inflating sleeping mat (400 grams, well worth the weight) and sleeping bag inside and I could have slept anywhere (apart from that bloody bench!!)
They are quite breathable as well but I never bothered doing the top of the bivi up as it was quite warm.