GAWA external grilles are designed for fresh air intake and removal of polluted air from buildings. They consist of a round frame with fixed louvres installed in it, the shape of which prevents the penetration of precipitation from the street. On the inner side of the grille there is a protective mesh. Grilles in sizes from 100 to 315 mm are made of aluminium, and grilles in sizes 500 and 630 mm are made of black steel.