A roomy, breathable bivi bag

This bivi bag is made from air permeable highly breathable eVent fabric, which means it can be completely sealed without danger of suffocation. And it really can be sealed too, with a continuous Velcro flap over the long curving hood zip. The zip goes round the hood too, rather than across it, so there is no opening on the top of the bag. This gives good protection against rain and snow. The long zip makes getting in and out easy.

There’s also a zip-out mesh panel that allows for ventilation without letting the midges in. The Ascent is roomy enough for a winter sleeping bag and a full length sleeping mat though little else. The fabrics are substantial and this bag should be durable. It is fairly heavy though and quite bulky when packed.

If you’ll be using a bivi bag regularly under the stars it could be worth the weight given the protection and the breathability but for occasional use there are lighter weight, less expensive alternatives. That said, the price is reasonable given the eVent fabric.