Product Description     Removable and replaceable UGGpure insole that keeps feet dry and cozy. Exclusive vibram outsole and a repeating lug tread pattern that provides maximum surface contact for traction and malleability at the footbed natural flex points. If you are unsure which shoe size to purchase, please follow the following steps-1.Draw a straight line, longer than your foot, on a piece of paper. 2.Place the paper on a flat surface. Stand on the line with your heel and longest toe centered on the line. If measuring a child's foot, it may be easier to hold the paper up to their foot. 3.Place a mark on the line at the tip of the longest toe and at the back of the heel. 4.Repeat steps 1-3 for the other foot. 5.Measure the distance between the marks. Taking the larger of the two measurements, use the conversion chart to find your correct shoe size.