Aluminium profile 25x25x2 mm; 11mm OSB Wood (Not Chipboard) on Seat and Back Parts; 30 cm length welding that provides more strength in the leg profile (Not Spot Welding); Back front sponge, 3cm 32 density gray sponge; Seat foam, 600gr 55 density hardness 7cm cast polyurethane; Back Back 3mm duralite on 1cm white sponge, covered with upholstery fabric; Easy to Stack Up to 12 Pieces; Many fabric and profile color option