Underpart: White plastic-laminated Steady wheel-elevatesystem = movable in each height on easy-rollingtwincastors. Upholstery: = Hard wearing and long working life Construction: Upholstery-Basis: Laminated wood panel Upholstering: With multilayered foam in volume weight 75. On principle we only use pure Polyurethane rigid foam. On principle we don’t use foam sandwiches as a preparated mixture of varying kind of foam rubber flocks.