Recycled material such as papers, cardboard, plastics.
Mask.
Copper, sulfur, scrap iron, armored cars, petroleum products, artificial environment systems and equipment, refrigeration and heat pump air conditioning systems and supporting products, fire fighting equipment, civil air defense and chemical protection equipment, ventilating fan ventilation pipes and supporting products, plumbing and heating equipment and supporting products, cooling towers, water circulating water treatment equipment, water supply equipment, motors and power transmission and distribution equipment, solar hot water equipment, photovoltaic equipment, led equipment, fresh air equipment, purification equipment, environmental protection detection and sludge, sewage and waste gas treatment equipment, dust removal equipment, pressure vessels, metal steel structures. carbon catalysts medical device sales.