9 Electronic detectors, namely, electronic-based instruments for measuring environmental parameters including air quality, carbon monoxide (CO) levels, ozone (O3) levels, formaldehyde (HCHO) levels, oxygen (O2) levels, ammonia (NH3) levels, hydrogen (H2) levels, chlorine (CL2) levels, hydrogen sulfide (H25) levels, combustibles (LEL) levels, and volatile organic compounds levels