This piton keeper ring is shown in catalogs having the manufacturer unmentioned, or it is shown as a Troll product, even a Edelrid product. Ashby Robertson of Vertical Archaeology has a thought that the piton keeper ring may be created by a third party, who allowed the climbing companies to list it as their product.... without exclusivity.
Piton Carriers - Au Vieux catalog 1972
Two different metals
This green version of the Anneau Rectangulaire is the most common I have seen.
Smaller version of the Anneau Rectangulaire (AKA: Haken-Schani), red/brown colored.
Piton Carriers - Au Vieux catalog 1976
The Anneau Heart shape piton carrier is also named the Anneau Rectangulaire.
Hei-Ha catalog 1969
Hei-Ha catalog 1975
The spring clips are 1/4" longer on the green version than the non colored version.