Instruct: Classify Amazon reviews into positive or negative sentiment
Query: With Spira you are ' Walking on air'.

I bought my first pair of these shoes about two years ago. I'm a nurse and walking on concrete floors over 8 hours a day. I love these shoes. I've bought three pairs and plan to only buy the Spira brand for quality and comfort. But don't wear them if you are having an MRI. Remember the metal spring.