Instruct: Classify a given review as either positive or negative.
Query: Defective product

We bought this item twice. The first time, it was defective and wouldn't work (it made a dull sound all the time, and no additional sound at all when put in contact with water, as per the test described on the instructions sheet), so we returned it to Amazon (thanks for your excellent returns policy!) for an exchange. When the 2nd item proved just as defective, we got our money back. Don't waste your money on this junk -- buy something more expensive and substantial.