Original white plastic Heimsyphon brand Carbon dioxide capsule/charger key, probably manufactured from around the late 60's to early 80's, and designed to fit the Heimsypon syphons of this period (we have also found this fits Merkuria Kovocas syphons too).  Produced in a heavy weight white plastic with a threaded alloy insert; designed to fit the C (8 gram) sized CO2 capsule, which remains widely available to this day.