Hydrostatic head rating of 10,000mm , designed to allow the user to create a twin skin on their R-Series 1-Man bivvy. Increases warmth in the winter and helps to keep you cooler in the summer, vastly aids the reduction of condensation. Creates additional storage space for items such as waders, bait etc. Large front and rear mozzy mesh panels, two-way letter box style door with three door options, mozzy mesh, clear PVC and solid. Made from hard wearing, breathable polyester fabric.