ISI brand co2 cartridges contain 8 grams of quality food grade co2. ISI offers the quality and taste that discriminating consumers want. Since they are made exclusively for ISI soda siphons, these chargers are perfectly designed and filled . . . and they’re backed by 100% quality control testing. Each case contains 36 boxes of 10 cartridges. 360 co2 cartridges in total.