Features:Exhaust air grille,The frame can take-down from the blade.It is easy to clean and take-down.The angle of blade is 45 degree installed.It can be used in in the outlet to return air. Material: aluminum. Standard size:300*160,300*300,400*400,595*295,595*595. according to the request (more) Color:mill finish or RAL 9010, can also follow customer's requirements.