Feature:
Material:Aluminium alloy/Stainless steel/Galvanized sheet
The vane is fixed, which are both 45 degrees.
Natural anodized aluminum finish or powder coated
OBD or Filter(Nylon or aluminium alloy)is optional.
Easy installation and maintenance

Functions: for sidewall/ceiling as return air, avoid direct ventilating. 

Use :in washroom, toilet, lift pipeline, hole decoration as well as in warehouse etc.