The Auto Hydrostatic Mustang Life Jackets Re-arming Kit contains everything necessary to re-arm your Mustang Survival Auto Hydrostatic inflatable PFD after deployment. It includes the cap body a 33 gram CO2 cylinder a metal key and the re-arming instruction manual. Regular maintenance of PFDs with the Mustang re-arm kit helps to ensure they re ready to be used when you need them most. Replace the inflator cap and body before the expiry date on the cap passes to keep your equipment at peak condition.