Made of solid acacia wood. Designed for outdoor use with slats and galvanized screws. All middle shelves have the same dimensions in this Modular Nest Insert system, allowing you to arrange your workspace entirely according to your own taste and style. A stainless steel grill at the bottom and an acacia shelf at the top? It's up to you. You can choose between shelves made of stainless steel grill, stainless steel, or acacia. Having trouble deciding? You can always change it later.