http://old.chairman.ru/eng/goods/boss/boss_96.html Properties of the model: Upholstery Microfiber Armrests Plastic with microfiber pads Tilting mechanism Tilt control mechanism with locking position Support cross Plastic Gas lift Germany DIN 4550 3rd class Castors BIFMA 5,1 standard (US). Rod diameter 11 mm. Frame Nonmonolith Stuffing Standard polyurethane foam 25-40 kg/cu.m. Recommended maximum load 120 kg. Warranty 2 years