Features: (10) 8-Gram CO2 cartridges. (1) oiler cartridge Description: The Byrna Technologies 8 Gram CO2 Cartridges are an essential accessory for your Byrna SD Launcher. They quite literally cannot live without them. The cartridges are the fuel of the SD Launcher. Each cartridge is good for 15-20 rounds. It also comes with one oiler cartridge that is used for maintenance every 10 CO2 cartridges you use. If you have a Byrna SD Launcher, you need these! Interested in more accessories? Check out our knife accessories section!