Installation, repair and maintenance of surgical, medical, dental and veterinary apparatus, and parts and fittings for the aforesaid goods; installation, repair and maintenance of apparatus for providing a sterile environment in which to conduct surgery, and parts and fittings for the aforesaid goods; installation, repair and maintenance of clean rooms, air purifiers, air extractor installations and sterilization devices for clean rooms, air purification filters, air filters for the purpose o...