NOS NOS introduces 180 degree bend nitrous bottle blowdown tubes. Each tube made from 1/2" 6061-T6 aluminum and available in blue or black anodized finishes. This type of tube is necessary when mounting a nitrous bottle inside the passenger compartment of a vehicle. It directs the nitrous outside of the vehicle in the case of an over-pressurization event. The 180-degree bend may be necessary for some nitrous bottle installations where the standard 90 degree tubes will not work.