This is an extra standard
NATO 40mm x 1/7” DIN 3283 filter port plug supplied with the MESTEL SGE150, SGE400 masks.
It will fit and plug any
NATO 40mm x 1/7” filter port in any mask model from any mask manufacturer.
How to use:
If your mask has more than one filter ports, all filter ports have to be either plugged by the filter you are using (up to 2 filters per mask) or a filter plug to work correctly!