To fly with a Restube, read the information in the instructions and the accompanying Quick Check Guide. Here below you can find the printing template of the official permission of the LBA, which you should print with the cartridges when carrying. Ideally, you pack the cartridges, the permission and the Quick Check Guide together in a transparent plastic bag and have your Restube ready when being asked what you need the cartridges for. When flying cartridges are not allowed to be screwed into your Restube. You can easily screw the cartridge in and out yourself. Have a nice trip and lots of fun!