Feature:
Material:Aluminium alloy/Stainless steel/Galvanized sheet
The blade is fixed, which are both 45 degrees
It can be opened like a door,which is easy for cleanliness.
Can add OBD or fliter as you need
Natural anodized aluminum finish or powder coated

Functions:mainly used for return air of ceiling and side walls, avoid direct ventilating.
Use :in washroom, toilet, lift pipeline, hole decoration as well as in warehouse etc.