Instruct: Classify Amazon reviews into positive or negative sentiment
Query: very good product, but it failed within 8 months

The product works very well, and I recommend it. However, after 8 months of use the cuff failed to inflate due to a leak. The pressure reading would read around 60 and the pump would stay on until the unit is turned off manually. Customer service referred to this as "hovering". I sent the unit back under warranty and they replaced the cuff and it is working fine now. I give it 4 stars instead of 5 because it failed so quickly, and it cost me about $14 to ship it both ways for warranty service.