Superfeet Trim To Fit-BlueDesigned primarily for tighter fitting footwear, Superfeet Trim To Fit Blue insoles are very versatile. Provides excellent biomechanical support for the widest variety of foot shapes. Featuring AgionŽ antimicrobial top cover treatment to help reduce bacteria and help prevent foot odor. Ideal for feet with low-to-medium arches that cannot tolerate maximum support. Recommended footwear: Cleated athletic footwear, running and hiking shoes, and all types of casual and dress shoes. Sizing: A= women's shoe 2.5 - 4. B= women's shoe 4.5 - 6. C= men's shoe 5.5 - 7, women's shoe 6.5 - 8. D= men's shoe 7.5 - 9, women's shoe 8.5 - 10. E= men's shoe 9.5 - 11, women's shoe 10.5 - 12. F= men's shoe 11.5 - 13, women's shoe 12.5+. G= men's shoe 13.5 - 15. H= men's shoe 15.5 - 17. J= preschool shoe 11.5 - 13.