Solid. Steel security grilles
Old fashioned, powder coated steel security grilles.. Approx 50 yrs old and not a spot of rust anywhere. Horizontal bars are 25mm square and verticals are 10mm with approx gap of 120mm Four are 400mm high by 1800 mmwide, one is 600 high by 400mm wide and 3 are 1000mm high by 1800 mm