40 Pack, durable non threaded weld sealed stainless steel construction Super-charged cartridges with 8 grams of pure CO2, ideal for vintage guns Compatible with ISODA, Soda Sparkle, Mastrad, Ukeg 64, and all standard 1 liter soda siphons Not compatible with the Hamilton Beach Fizzini. Also great for antique pellet gun and toy car propellant. This pack of 40 Super-charged cartridges with 8 grams of pure CO2, will surely produce the best seltzer you've ever tasted! Compatible with ISODA, Soda Sparkle, Mastrad, Ukeg 64, and all standard 1 liter soda siphons. Not compatible with the Hamilton Beach Fizzini. Ideal for vintage guns, antique pellet gun and toy car propellant. Durable non threaded weld sealed stainless steel construction.