This spiral duct is made specifically to fit the Nano P8XEi fans and is specialized to conduct static charges away from the airflow. Static buildup could create a spark that would compromise safety in explosive environments.
The duct consists of graphite fibers that conduct any charge that could build-up as a result of the airflow. Airflow through the standard duct builds up static charges much in the same way as walking across carpet does.
The special clip on the end of the duct must be connected to a grounding post that carries the charge back to earth ground – usually this is accomplished through the ground plug of the electric motor.
The confined space duct is available in either 15 ft or 25 ft lengths.