Crux B1 Recce Bivvi Bag
Bivvi bags come in all shapes and sizes, but this is one of the smallest I've come across so far. It's a full length bag with a half length zip down one side. It is a straight bag, no hoop or poles to keep the material off your face. It weighs 514g and packs down to something the size of a kitchen roll, smaller if really compressed. The upper 2/3 is X-Tex meaning that it is pretty breathable, whilst the base is a harder wearing lightweight waterproof material. In reality it's proved to be watertight and I'm pleased to say that there's been little in the way of moisture on the inside on waking in the morning.
It is 235cm long so enough room for a small amount of kit to be stored inside at the head end, but not enough for a large rucksack. It is 75cm wide at the chest, tapers a little towards the head, and is 50cm at the base. I have found that there is room inside the bag for a mattress and a sleeping bag. There's only a single external loop at the head end, presumably for hanging to dry / air, but also useful for pegging it down to stop it blowing away when you are not in it. I'd have liked to see a couple of loops at each end for this, but then that would also mean supplying pegs so I see why there aren't. Getting into the bag (and packing it with a mattress and sleeping bag) was a doddle thanks to the half length zip. The zip has a generous baffle to keep water from passing through it, and the zipper itself has reflective material so it's easy to find in the dark with a torch. It retails at £174.99. I've used it both to sleep out without a tent, and also inside a tent simply as an extra layer for a lightweight sleeping bag. It’s snug inside, but there's enough room inside to turn around and get comfortable. All in all I'm very happy with it.