The Mustang MA7270 Re-Arm Kit includes 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. This re-arm kit is for vest model numbers: MD3001, MD3002, MD3017, MD3019, MD3031, MD3032. Mustang Survival advises customers to use only Mustang brand re-arm kits for their vests, due to the importance of the apparatus we must agree with that sentiment. Please use only Mustang Survival re-arm kits with your Mustang Inflatable Vest. Use of other re-arm kits may result in improper operation or failure to operate and will void the product's warranty.