The Kirby Morgan 550-081 regulator mount nut is used to secure the demand regulator to the helmet is now made of silicone bronze. The previous material was stainless steel. The silicone bronze regulator mount nuts will be used in assembly and available as spares as soon as our stock of stainless steel regulator mount nuts run out.
Any old stock of the stainless steel regulator mount nuts can be used without issue.
This decision is based on the shift to using only stainless steel material for our regulator bodies in the future. Switching to a silicone bronze material will decrease the possibility of galling between two stainless steel materials.