Where do you find Iskra ration packs?

Excuse me, could you kindly assist me in locating Iskra ration packs? I've heard they're quite popular among those in the crypto and finance circles, but I'm having trouble pinpointing their exact availability. Could you perhaps provide some insight into where one might go to acquire these packs? Are they available online, or do I need to venture out to a specific store or location? Any information you could offer would be greatly appreciated.