In Ruling NY N304567, Customs and Border Protection (CBP) determined the classification of a storm glass weather forecaster. This item uses a liquid mixture of distilled water, potassium nitrate, ammonium chloride, ethanol, and camphor to predict atmospheric change. The liquid in the glass appears cloudy when precipitation is approaching; when crystals are visible in the liquid, humid or foggy weather can be expected; a cloudy glass with small stars indicates thunderstorms; and a clear glass predicts calm weather. The glass orb is sealed completely airtight, housed on a wood pedestal, and secured with brass fittings.

CBP determined that the applicable subheading of the storm glass is 9025.80.1500 HTSUS, which provides for Hydrometers and similar floating instruments, thermometers, pyrometers, barometers, hygrometers, and psychrometers, recording or not, and any combination of these instruments; parts and accessories thereof: Other instruments: Other: Barometers, not combined with other instruments. The rate of duty will be 1% ad valorem.