Effective August 4, 2007, the TSA again permits the CO2 cylinders with an Inflatable PFD through their security checkpoints. TSA Screeners across the United States have been trained already and are prepared to let these through. Look under "Disabling Chemicals & Other Dangerous Items" for specifics: http://tinyurl.com/ptxdw Remember though, it is still each airlines choice whether to allow these on their airplanes and each sets their own policies (roughly 1/2 allow them and 1/2 don't). Check with your airline (and connecting or return flights) or their websites to make sure they allow them before you travel. We recommend to carry your PFD cylinders in CHECKED baggage and not in your carry on.