Shell - Cold cured injection molded polyurethane shell. Internals - Support frame structure of mild steel – Ø12mm rod connected to main frame using 30 x 6mm strips. Seat & Back - PU foam with Density of 30 kg / m3 &Seat cushion: 42-45kgs/m3. Base - Die-cast aluminum 4-prong swivel base in chrome finish without hydraulic gaslight. Bush - Nylon