What type of cylinder is used to inflate some inflatable life jackets?

Inflatable life jackets utilize a CO2 cylinder for inflation. Carbon dioxide is chosen because it is easily stored in a compressed form within the cylinder, allowing for a compact and lightweight design. When the life jacket is activated, the CO2 is rapidly released, inflating the jacket to provide buoyancy.

Other gases like helium and hydrogen are not typically used in this application; helium is lighter than air and would not provide the necessary buoyancy for flotation, while hydrogen poses safety risks due to its flammability. Air cylinders are generally used for different applications, such as scuba diving, but are less practical for life jackets where instant and reliable inflation is critical.