@Alive, this is GREAT info! Going to edit my post above and add that in! This is exactly why this community is so good. I searched and searched on the 7800 and assumed the buttons had to do with size, but couldn't find it. So glad you got that info!
Just to clarify what you are saying on the MSA Advantage 1000 Respirators... There are two different types of strapping: one that has large plastic "rivets" that hold the strap to the mask and another style, that does not, correct? We know both a Large and a Medium mask are used in the show (don't know how many of each), but at least from the photos I have posted, it appears that the Medium mask has the plastic rivets and the Large mask does not. Is that correct?
Just to clarify what you are saying on the MSA Advantage 1000 Respirators... There are two different types of strapping: one that has large plastic "rivets" that hold the strap to the mask and another style, that does not, correct? We know both a Large and a Medium mask are used in the show (don't know how many of each), but at least from the photos I have posted, it appears that the Medium mask has the plastic rivets and the Large mask does not. Is that correct?