Caracas rain boots by Kuling. The boots have a rubber upper. They have a bonded lining, welded seams, removable insoles, a sole with rough tread for a sure step and a pull tab at the back. – Waterproof.– Windproof.– Upper: Other Materials.– Lining: Textiles.– Sole: Other Materials.– Please note that when you purchase shoes for your child, you should select a size that is 1.5 cm larger than your child's foot. Wellies and boots should be up to 2 cm larger, for extra socks and insoles.Size Guide (Insole): 21 = 130 mm22 = 140 mm23 = 145 mm24 = 150 mm25 = 160 mm26 = 165 mm27 = 170 mm28 = 180 mm29 = 185 mm30 = 190 mm31 = 200 mm32 = 205 mm33 = 210 mm34 = 220 mm35 = 230 mm