I went to Fleet Feet store and was told I have inflexible arches because they are very high. I was given the recommendation to purchase Superfeet GREEN Full Length Insole Size B, in addition to Balega socks, and life has been so much better ever since. Granted they were more expensive, but I have more energy throughout the day and I do not come home with sore feet after a day on the job. I work as a nurse and am on my feet for 12 hrs per day. I used to come home and get foot cramps every night with super sore, tired feet; however, this combination has been an amazing Quality of Life Improver!!!