6 cartridges - NRS 16g C02 Re-Arming Kit, For Life Jacket, with 3/8" thread.

They have never been used. The company sent me the incorrect thread size. I couldn't return item. 
Green arming pins are included.
 

The NRS CO2 Re-Arming Kit lets you re-arm the CO2 inflation device on your NRS Self-Inflating PFD so it's always ready when you need it.
  • Includes one 16 gram replacement CO2 cartridge and arming indicator tab for use with the first generation NRS Zephyr PFD.
  • If you are flying with your Inflatable PFD, the Transportation Safety Administration (TSA) says on their website, "You may bring a life vest with up to two CO2 cartridges inside, plus two spare cartridges in your carry-on or checked bag." Be aware that individual TSA agents may not have read that particular regulation.
  • This item contains hazardous or flammable materials and is restricted to surface shipping only. Cannot be sent to P.O. Boxes, Alaska, Hawaii, APO, FPO, U.S. Territories or international addresses.