Strictly speaking, I just wanted to test whether you can also produce waterproof fabric with the "Pattex Repair Silicone". Then I remembered an old NVA tarp. I also had some parts of an RG-UF / M rebreather left. Fast now is an complete O2 rebreather emerged. The really new thing is the coating with the repair silicone and the conversion of the RG-UF / M scrubber for filling from the top. The rest is similar to my replica of the "Medi Nixe" from here: Replik. The whole thing was a bit simpler, the scrubber is firmly installed.