What are the specifications for a replacement CO2 cartridge for the CI-301LA?

The CO2 cartridge is 16 grams and it is threaded . The thread size is 3/8 inch, 24 thread. The cartridges may also be sold for things such as beverages, bicycle tires or paint-ball/air guns. Here are a few webpages with the correct cartridges for sale: Bike Tires Direct- CO2 cartridges Google shopping search- CO2 cartridges.