The metal ventilation grilles are made fully with stainless or galvanised steel sheet and coated with a durable epoxy finish. They are fitted with insect screens. They provide the ducting with a good barrier against weather conditions. The metal grilles are available in various shapes: round, square, rectangular, and in a wide range of sizes from ø 100 mm to 150 mm (for the round type) and from 70 mm x 140 mm to 320 mm x 420 mm (for the rectangular type). Non-standard versions include grilles up to 400 x 45 mm in size, used e.g. in furniture. Depending on the grille type, the grilles come in white, chrome, brown, black and graphite.