It belongs to 37 categories: 3706 mechanical and electrical equipment installation and repair (1) electrical equipment installation and repair 370003, office machinery equipment installation, maintenance and repair 3700 14, air conditioning equipment installation and repair 370028, kitchen equipment installation and repair 370035, irrigation equipment installation and repair 370053, machinery installation, maintenance and repair. Install and repair refrigeration equipment C370003, install, maintain and repair computer hardware 370 1 16, repair worn or partially damaged engine 370 1 18, and repair worn or partially damaged machine 370 1 19.