... 2. Round air outlet connected with flexible pipe 6'8"Bathroom Exhaust fan/ventilation fan 1. Low noise, little vibration ... 2. Round air outlet connected with flexible pipe 6'8"Bathroom Exhaust fan/ventilation fan1. Low noise, little vibration 2. ... kinds of non-windows ceiling. for conference rooms, restaurant, receptionroom, bathroom etc3. Exhaust effectively indoor polluted air, wet gas, smoke, dust4 ...