The EVA, heat mouldable insole has a built in rearfoot varus angle, a poron tear-drop shock dot and heel grid to reduce slippage inside a shoe.Covered in a bonded fabric these insoles alleviate the symptoms associated with flat footedness or excessive pronation. Sizing According to shoe size. When sizing orthotics, if your patients shoe size falls between orthotic sizing, then as a rule of thumb, size down in orthotic.