37 Inspection in the course of building construction, Maintenance and repair of combustion engines and land vehicles, Electro technical products in the nature of [indicate type of products more specifically], mechanical engineering products in the nature of [indicate type of products more specifically], heating, air-conditioning, cooling and ventilation equipment, boats and vessels, thermic plants and their components, installation and erection of heating, ventilating and cooling equipment, installation of cogeneration plants for power and heat generation, and installation of emergency power generators; leasing of construction equipment and tools for machine and plant construction