The M.I.T. 100 Inflatable Re-Arm Kit contains everything necessary to re-arm your Mustang Survival M.I.T. 100 manual and automatic inflatable PFDs after deployment. The automatic inflator bobbin on all automatic PFDs should be replaced on a regular basis. This re-arm kit is for model numbers: MD2014, MD2015, MD2016, MD2017. 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.