33g CO2 cylinder for inflatable life jackets., , When you buy a new inflatable life jacket, it comes complete with CO2 cylinder and cartridge/capsule trigger, if your inflatable life jacket deploys, you need to reload it with a new gas cylinder and trigger., , How do I know which CO2 cylinder is right for my inflatable life jacket?, , Inside the life jacket on the inflatable lung, information is printed on which gas cylinder fits your life jacket.