Protective mask for airborne toxic substances
Respirator module with speech transmission and exhalation valve
Respirator speech transmitter
Respirator speech unit/outlet valve
Respiratory mask and microphone mount for use therein
Retrofitting gas mask voice amplifier unit with easily actuated
Retrofitting gas mask voice amplifier unit with easily actuated
Speech diaphragm and exhalation valve
Speech transmission adaptor for use with a respirator mask
Speech transmission adaptor for use with a respirator mask
Valve for respirator
Valve-talking device
Voice transmitter for a breathing protective mask