... as demand)Motor bearing, national grade. V-belt, A -type belt, imported from Korea. Shutters, galvanized board, 0.8 ... assistant by computers, which maximizes the effectiveness of the fan. Ten strict procedures that consist of airflow test, noise ... ≤643801000x1000x450175USDZRP-13801270(50in)50≥1400480001500≤643801380x1380x450235USD ZR series wall-mounted push-pull centrifugal ventilating fan