Asura 16 Gram CO2 Threaded Cartridges 16 gram CO2 cartridges filled with pure food grade gas 3/8" thread with 24 threads per inch 30 pack in box Instantly refill your flat tire when pairing with a CO2 tire inflator Revised design, works with most co2 inflators that takes threaded cartridges. Tested compatible with: Asura 2sec CO2 Inflator, PRO BIKE TOOL CO2P-R01, Lezyne Twin Speed Drive, SRAM Mini Twist Inflator, Genuine Innovations Ultraflate