Shower Niche Recessed Shelves100% WATERPROOF: We have the product done by injection molding which the part is to be one whole piece, no penetration of water, no leakage and 100% waterproof. DESIGN BY AMERICAN PROFESSION TEAM: Round corners, no sharp edge with safety; 4 side pre sloped keep water off the shelf. EASY INSTALLATION: Surface with texture friendly with thinset application and easy for tile, stone or mosaic tile. Dimensions: Inner dimension:14"*14"*3. 88", 14"*14"*3.