Nang cylinders, also also known as whipped cream chargers, are small steel canisters crammed with nitrous oxide

https://volcano-enforce-46089.uncrn.co/blog/understanding-the-mechanics-of-n2o-nang-cylinders/

Nang cylinders, also is called whipped cream chargers, are small metal canisters full of nitrous oxide, in the main used to create whipped cream quick in culinary applications.