An electrical inspector denied the use of this Article 360, ⅜-in. flexible metallic tubing (FMT) because it was used in lengths longer than 6 ft with low-voltage fire alarm equipment. Section 360.20 indicates that FMT smaller than metric designator 16 (trade size ½-in.) can't be used, except when it will be installed in accordance with 300.22(B) for ducts or plenums used for environmental air (in lengths not to exceed 4 ft) and 300.22(C) (with no length restriction) in other spaces used for environmental air. The installer challenged the inspector, and suggested a “tug of war” with the same size of flexible metal conduit of the same length, and proved that the flexible metallic tubing was more durable. I wonder how many inspectors would approve the use as described?