The Automatic Inflatable Re-Arm Kit contains everything necessary to re-arm your Mustang Automatic Inflatables after deployment. The automatic inflator bobbin on all automatic PFDs should be replaced on a regular basis. For model numbers: MD3001, MD3002, MD3017, MD3019, MD3031, MD3032. Use only Mustang Survival re-arm kits. Use of other re-arm kits may result in improper operation or failure to operate and will void the product's warranty.