A threaded 16g CO2 cartridge to get you back up and riding. Get several and keep them handy. This cartridge works with all Genuine Innovations inflators that have a 38 24 thread. Works with Ultraflate, Ultraflate Plus, Ultraflate Pro, Microflate, Air Chuck, SecondWind IH, SecondWind MTB. Due to federal shipping restrictions regarding products with hazardous or flammable materials, this product can only be shipped via ground transportation. Were sorry, but Next Day Air, 2nd Day Air, USPS Priority or Express shipping are not available for this item. Additionally, this product cannot be shipped to Canada, Hawaii, Alaska, Catalina Island, Puerto Rico, APO, FPO or international addresses. Thanks for your understanding..