Orion 12g charger

I got this stripper charger as shown. What gun/device fires this and how does it load?

Vlad, this is used only for transportation and is placed in the buttstock and hammer of the Orion signal pistol. This is the original factory configuration with three red aerial flares and one white aerial non-distress flare.

Here is an excerpt from a 1996 brochure by Standard Fusee Corp. (since 2000 designated Orion Safety Products):