Dräger model BG4
The successor to model BG174
The BG 4 closed-circuit breathing apparatus is a regeneration device with a pure oxygen supply in a pressurized design. The low positive pressure in the entire breathing circuit prevents the penetration of harmful substances from the ambient air. The breathing air circulates in a closed breathing circuit. The CO² absorber binds the carbon dioxide contained in the exhaled air. The breathing air is enriched with oxygen from the oxygen cylinder. Approval 2008
Therebreathersite was founded by Jan Willem Bech in 1999. After a diving career of many years, he decided to start technical diving in 1999. He immediately noticed that at that time there was almost no website that contained the history of closed breathing systems. The start for the website led to a huge collection that offered about 1,300 pages of information until 2019. In 2019, a fresh start was made with the website now freely available online for everyone. Therebreathersite is a source of information for divers, researchers, technicians and students. I hope you enjoy browsing the content!