Half sizes are made by adding the Half Sizer Insoles which are designed to go under the existing insoles to obtain a half size fit. Our half sizer insole are a cut-to-fit foam insole just cut along the dotted lines printed on this 3mm flat foam isole and place it UNDER the premium insole. It will make the rain shoes fit a half size smaller. Two insoles per pack. The Half Sizer Insoles will be included free with any half size rain shoe order.