From the BYRNA website;
Maybe you’re one of the 134 million Americans that are flying commercial to your destination. In that case, your Byrna launcher can come along with you in your checked baggage, along with any type of Byrna projectiles, and they do not need to be declared like firearms do. While the FAA technically allows CO2 cartridges on commercial flights, the TSA has some policies in place that may prohibit them. If you’re carrying an SD, consider mailing a couple of 8g CO2 cartridges to meet you at your final destination. If you’re carrying a Byrna LE, you are likely to be able to grab some 12g CO2 cartridges at any sporting goods, hardware, or big box store after arriving.
