Since they are made exclusively for isi cream whippers, isi chargers are perfectly designed and filled and they’re backed by 100% quality control testing. To be sure you serve the very best, buy only the very best. Cream chargers made by iSi are leakproof, have no expiration date, and are made of 100% recyclable steel. Ships via ground only. 8.4 Gram N20 Chargers.