The Rab Alpine Bivi bag is one of the best available, it is well made from Lightweight 3L 15d eVent® fabric which means it is waterproof and breathable. Many manufacturers claim this but in practice you always seem to end up cold and damp in the morning. This is not the case with the Alpine bivi bag, it really does allow moisture to escape and almost eliminates the problem of condensation.
Another problem with many bags is durability, the Apline bag overcomes this by having a tough 70d coated nylon bathtub floor which keeps you completely dry, even when sleeping on waterlogged ground or in slushy snow.
It packs down to a reasonable 30cm x 10cm (12 x 4 inches) which is good considering its excellent durability and ruggedness and weighs only 495g.
With the hood completely zipped up, the bag offers good all round protection from wind, rain and snow, as well as from insects such as mosquitos.
The bathtub base refers to the fact that the groundsheet part of the bag comes up high around the edge of the bag leaving no weak point for water to get in. This is great when it rains overnight and you find yourself sleeping in a puddle of water – you will still be nice and dry inside!
Below you can see the bag opening, the wide mouth allows you to get in and out easily, even in cold conditions when you may be wearing a down jacket. The 235cm wide bag is roomier than many and has enough space for you to roll over inside it, very useful when trying to find a comfortable postion in which to sleep.
Overall an excellent bivvy bag, one that will last many years and can be used in all conditions. This is a quality piece of kit and a worthwhile investment for any outdoor enthusiast.