Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great for allergies! Small and portable.

Got this for my mother that has been experiencing post-nasal drip and sneezing/coughing for weeks. Within a few days, no more! Small, easy for her to handle and carry from room to room (will have to buy her a second one). Mom says it's near to perfectly quiet, but says the small amount of noise is worth it for the way that she's feeling. Will have to get one for my own allergies as well!