Our Mox Boxes are filled with shoes to grow with your baby during their first and second years of life. Our inspiration behind the Mox Box was to take the guess work out of sizing so our customer's never have to worry about exchanging shoes. To ensure ordering a proper size, please measure your child’s foot prior to ordering. We recommend adding 1/2″ to your child’s foot measurement for growing room SIZING: First Year, sizes 1, 2 and 3 (styles as shown): sz 1 0 - 4 months soft sole 3.7" sz 2 3 - 10 months soft sole 4.1" sz 3 7 - 15 months soft sole 4.5" Second Year, sizes 3, 4 and 5. (styles as shown. sz 4&5 have rubber soles) sz 3 7 - 15 months soft sole 4.5" sz 4 1 - 1.5 years hard sole 4.9" sz 5 1.5 - 2.5 years hard sole 5.3" MATERIALS: - Made from our soft vegan leather. - Waterproof