Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good for 30 days

Buyer beware! This product was intended for very limited use (30 min max). My father has been using this product since Christmas and for 30 days it worked. Now the motor in the unit squeals and makes a lot of racket. So for around $15.00 over 30 days it cost me 50 cents per day. I will now shop for a quality product!