An extra inner bladder for the hull is always a good to have. Made from specially developed and reinforced TPU-coated fabric, it’s both light and strong. By the way, we’ve used the same material used for aviation life jackets. In one end is the specially developed check valve with its cover and with velcro rings in both ends to position the inner bladder in the hull. In case you get stranded we’ve coloured the bladder bright red. Simply remove it from the hull, inflate it and bind it to the top of a tree to be easily spotted from the air.