the advantages of our exhaust fan: 1)height,width,thickness,780,780,420mm 2)big air volume,no distortion,etc. the advantages ... m3/hTotal pressureNoise decibelsImport powerRated voltageHigh mmWidth mmThick mmJLF(a)-780(30in)7109609602300075≤70550380780780420JLF(a)-830(32in)72066014002200060≤60550380830830400JLF(a)-900 ...