The original Survival Zone was my most used bivi bag for 15 years so I’m very familiar with this lightweight inexpensive minimalist bag
It’s similar to the Alpkit Hunka and Snugpak Bivvi, though larger than either. The weight is between those two, the price slightly higher than the Bivvi, though still reasonable. The Pertex Shield fabric is adequately breathable.
The bag fits round a sleeping bag. A sleeping mat will fit inside but is better used outside so the Survival Zone can move with your sleeping bag. There’s room for a winter sleeping bag and a few clothes as a pillow in the hood but nothing else. The cordlock for the hood drawcord is hidden in a tunnel of material on one side of the hood. It can’t dangle and hit you in the face but loosening the hood from inside is slightly awkward.
The shaped hood can be closed to a tiny hole but as with similar bags turning it upside down is the best way to keep out rain. The hood opens wide, which makes getting in and out easy.