37 Electrical contracting services, installation of electrical systems, electrical repair and installation of lighting, electrical repair and installation of electrical motors, electrical repair and installation of air conditioners, electrical repair and installation of heaters, repair of electric lights; general building contractor services, pipeline construction and maintenance, maintenance and repair of pipelines, repair and maintenance of air-conditioning apparatus for industrial purposes, repair and maintenance of boilers, repair and maintenance of booster pumps, cable laying, laying of cable, fire alarm installation and repair, repair and maintenance of fire alarms, traffic light installation, repair and maintenance; building maintenance and repair, maintenance and repair of heating installations, repair and maintenance of integrated circuits manufacturing machines and systems, repair and maintenance of gas water heaters, repair and maintenance of nuclear power plants, plumbing, plumbing services, plumbing contracting services, heating equipment installation and repair, freezing and refrigerator equipment installation and repair, repair and maintenance of boilers, repair services for electric generators and wind turbines; Installation of electrical and generating machinery, installation and maintenance of photovoltaic installations, installation and maintenance of solar thermal installations; masonry, laying of carpet, repair and maintenance of building scaffolds, working and building platforms, painting and repair of signs, Sign painting, general building construction contracting services, building construction services, bridge construction services, construction and renovation of buildings, construction and repair of buildings, construction of buildings, construction of airports, construction of medical establishments, construction of residential and commercial properties, road construction services, repair and maintenance of building scaffolds, working and building platforms, plastering services, laying and construction of pipelines, oil pipeline construction, factory construction, cementing services for oil and gas wells, air conditioning vent sealing services; building construction supervision; construction planning; consultation in building construction supervision; building inspection; project management in the field of building construction