9 Scientific, research, navigation, surveying, photographic, cinematographic, audiovisual, optical, weighing, measuring, signaling, detecting, testing, inspecting, life-saving and teaching apparatus and instruments, namely, hygrometers, air analysis apparatuses, air quality measurement apparatuses in the nature of particle counters, electronic based instruments for measuring environmental parameters including humidity, mold, bacteria, air quality and water quality; apparatus and instruments for conducting, switching, transforming, accumulating, regulating or controlling the distribution or use of electricity; apparatus and instruments for recording, transmitting, reproducing or processing sound, images or data; digital sensors for detecting and monitoring air quality, oxygen, carbon dioxide, fine dust, air pressure, temperature, carbon monoxide, humidity, nitrogen dioxide, ozone; downloadable software for monitoring and analyzing indoor air quality, room acoustics, and ventilation; downloadable software for monitoring and controlling indoor oxygen content, air pollutants, and humidity; blank digital or analog recording and storage media being blank recordable compact discs; mechanisms for coin-operated apparatus; cash registers, calculating devices, namely, calculators; computers and computer peripherals; diving suits, scuba diving masks, earplugs for diving, nose clips for divers and swimmers, diving gloves, breathing apparatus for underwater swimming; fire extinguishers