One 38 gram CO2 cylinder/inflator body, inflator cap with metal pull handle, metal key, and re-armimg instruction manual. Supports models MD3160 and MD3170. 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. Regular maintenance can reduce the possibility of inadvertent inflation. Refer to your Owner's Manual for maintenance schedule.