Pack of six, 16-gram Non-Threaded CO2 Cartridges from Genuine Innovations * One cartridge inflates 700x23c and 28c tires; MTB 26-inch x 1.95 2.4-inch tires; 29er 29x2.1-inch tires; and BMX tires * Two cartridges inflate: 700x35c tires * Fast in easy way to inflate tires without pumping * Compatible with Ultraflate, Ultraflate Plus, Ultraflate Pro, Microflate, Air Chuck, SecondWind IH, and SecondWind MTB pumps