All Nike shoes have letters on the insoles. Because the Nike insole does not have a letter logo, it must be fake. Some mid-range running shoes and trendy casual shoes do not have a Nike logo on the soles, but there must be a Nike logo on the insole. The correct version of the insole is very well shaped and latex It is high-density and has a letter logo underneath. All Nike shoes have letters on the insoles to distinguish the original and reverse versions.