Modern Penthouse Dining Chair Our reproduction of a famous dining chair. Our Modern Penthouse Chairs are high quality, exact reproduction using premium solid-core stainless flat steel, fully welded. Material : Solid JIS 304 (Japan industrial standard) stainless steel bars. Upholstery : Any upholstery fabric or EU Leatheroids, Avantgarde or semi-aniline cowhide leathers in stock. We can manufacture furniture to our customers' designs and specifications.