British SR6 Respirator

The SR6 or S6 respirator replaced the Mark 2 & 3 Light-Anti-Gas Respirators in service with the British army. The S6 takes the Nato 40mm filter and has curved lenses to improve the peripheral vision of the wearer. The mask has a tap inside that can be adjusted to inflate the inside of the mask to create a tighter seal with the wearers face.
The SR6 was worn by the SAS during the Iranian Embassy hostage crisis labelled Operation Nimrod
The S6 was eventually replaced by the S10 during the 1980s.