This version of Inner mask  comes, as photographed, complete with Valves and Valve discs (to prevent re-breathing Carbon Dioxide).

It is suitable for all versions of the Full Face-mask and it should have a service life exceeding five years.

Replacement of the old mask is easy but ensure the slotted groove is well seated and properly aligned on the mask manifold, when fitting. Soapy water will help as a lubricant to ensure seating home has been attained.

This version is grey (NR)  but yellow, silicone rubber versions are available - 

The compound for the grey mask is a mixture of natural, Neoprene and Strene Butadiene rubber, aimed at reducing skin reactions; for all-day-comfort and lending better strength, elasticity and durability to the mask.