KEEN Knotch Children's Sandal with Molded Ultralight Rubber Sole KEEN Knotch Children's Sandal (code 1025649) features two adjustable Velcro straps for easy on and off. Of course, there is a molded rubber sole that is extremely light and flexible. The shoe is treated with natural antibacterial Eco Anti-Odor technology, where the insoles of the shoes are filled with probiotic technology that naturally breaks down the smell of sweat without heavy metals or dangerous chemicals. The rubber sole of the sandals does not leave any marks, the sandals can be washed in the washing machine. Use a small amount of detergent, wash on gentle cycle and air dry. Material: textile, synthetic, rubber