These grilles are typically made from high-quality stainless steel, which is known for its ability to withstand the elements and maintain its appearance over time. The stainless steel bars or rods are often arranged in a horizontal and vertical pattern to provide a secure barrier, while the closely spaced bars ensure that the view is not obstructed. The Invisible Grills made of stainless steel material Grade 304 & 316 can be made in 2.5 mm & 3 mm diameters, providing a sleek and modern appearance.