Aqua Lung 1st Stage Back Up Split Ring ( fits inside HP housing, Poppet Retainer)
1st Stage Poppet Seat #8280-05
This Back Up Ring (Spacer, Washer) has a spiral split. Note that today the modern Aqua Lung regulators use a solid back up ring which is larger. One of the images shown, has a set of black and white BU rings with large on top ( modern size ) and black and white BU rings smaller below for Vintage size
From Vintage RAM to Vintage Conshelf, and modern Conshelf uses the same #8280-05 White Split Ring
Note - Vintage Mares regulators have the same identical size Back Up Ring to Vintage Aqua Lung models
