[ APPARATUS FOR CONTROLLING AND REGULATING TEMPERATURE FOR LABORATORY USE; SCIENTIFIC GLASSWARE FOR LABORATORY USE, namely, FLASKS, BEAKERS, TEST TUBES AND STORAGE TUBES, MEASURING GLASSWARE; ELECTRICAL AND ELECTRONIC APPARATUS AND INSTRUMENTS FOR SCIENTIFIC OR LABORATORY USE, namely, ELECTRICAL OR ELECTRONIC PH METERS, ELECTRIC, ELECTRONIC, OR ELECTROCHEMICAL OXYGEN MONITORS AND SENSORS FOR LABORATORY USE, ELECTRIC OR ELECTRONIC SENSORS FOR SENSING PH, DISSOLVED OXYGEN CONTENT IN LABORATORY ...

stereo speaker